Intersecting effects of sex/gender and autism on structural language: A scoping review

Abstract

Despite emerging awareness of gender diversity in the autistic population, our understanding of autism remains limited to cisgender boys and men. We conducted a scoping review to better understand how structural language skills (i.e. syntax, semantics, narrative) differ across sex/gender within autism, and how gender diversity is incorporated in such research. Five research databases were searched for articles that have autistic participants who were not all male, present quantitative results separated by sex/gender, pertain to structural language, and were published between 2000 and 2021. Twenty-four articles met inclusion criteria. One article demonstrated awareness of gender diversity beyond the binary (i.e. girl, boy). Overall, autistic girls performed better than autistic boys but worse than nonautistic girls. Autistic girls are less likely to share the same quality and magnitude of structural language difficulties as autistic boys, which may contribute to their underdiagnosis. Comparing autistic girls to nonautistic girls is more likely to reveal areas of linguistic difference and potential intervention targets. This research provides further support for developing sex/gender-aware diagnostic and support measures for autism. Broader awareness of gender diversity, as both a concept and a prevalent feature of the autistic population, is essential for researchers to continue learning about sex/gender interactions in autism.

Lay abstract

Research about autism is mostly about boys and men, even though many autistic people are girls, women, and transgender/nonbinary. We wanted to learn more about how gender interacts with language skills in autistic people, so we reviewed existing research articles on this topic. We also wanted to know how this previous research talked about gender. Included articles had to measure language skills for autistic people of different genders. They also had to be published between 2000 and 2021. Twenty-four articles met these requirements. We found that autistic girls showed better language skills than autistic boys but worse skills than nonautistic girls. This may be one reason that autistic girls are underdiagnosed compared to autistic boys. If we compare autistic girls to nonautistic girls instead, we can see more language differences and possible areas to target in interventions. This study supports the need to create diagnostic and support measures for autism that take gender into account. Also, only one article mentioned autistic people who are transgender or nonbinary. Researchers who want to learn more about gender and autism need to understand gender diversity and recognize that many autistic people are transgender or nonbinary.

Keywords

autism gender language

Girls, women, nonbinary people, and people of other marginalized gender identities have been historically excluded from autism research. Current clinical understanding of autism is, therefore, based almost entirely on autistic boys, including the diagnostic criteria and assessments used to identify autistic¹ people (Hus & Lord, 2014; Navarro-Pardo et al., 2021). Autistic girls and women are underdiagnosed compared to autistic boys and men (Halladay et al., 2015; Haney, 2016; Lockwood Estrin et al., 2021). This may be related to our limited understanding of how autism behaviorally manifests in girls and women as well as their camouflaging abilities: autistic girls and women tend to be skilled at observing and performing expected social behaviors for the purpose of blending in, although this practice can take a mental toll (Hull et al., 2017, 2020). When girls are diagnosed, they are disproportionately more likely to also present with intellectual disability or increased language impairments, as compared to when boys are diagnosed (Dworzynski et al., 2012; Giarelli et al., 2010; Wing, 1981). This is due, in part, to the fact that many girls present with subtler autism characteristics than commonly observed in boys (Bargiela et al., 2016; Young et al., 2018) and the fact that the core characteristics of autism may be expressed in a different manner. Autistic girls frequently experience social neglect (e.g. being forgotten), whereas autistic boys experience rejection (e.g. being disinvited from socializing; Dean et al., 2014). Girls tend to have more neurotypical-like, and consequently, more socially acceptable, focuses of intense interests than boys, such as animals or stickers (Lai & Szatmari, 2020). Autistic girls and boys experience differing trends of co-occurring conditions: autistic girls are more likely to experience eating disorders or obsessive-compulsive disorder, whereas boys are more likely to experience oppositional defiant disorder or attention deficit hyperactivity disorder (Posserud et al., 2016). Similarly, research centered on transgender and non-binary autistic individuals is limited but suggests that this group needs increased recognition and inclusive mental health services (Strang et al., 2021; Walsh et al., 2018; Warrier et al., 2020). Therefore, it is critical to begin to document how these gendered presentations differ to improve accurate diagnosis and tailored supports.

In the introduction, we build the foundation of this line of inquiry by laying out the following topics: First, we describe the importance of structural language. Then, we outline the concepts of sex and gender, as well as the growing knowledge about gender diversity in the autistic population. We then integrate these broad areas to discuss gendered language differences in neurotypical individuals and structural language in autistic individuals.

Structural language

One feature of sex/gender² interactions in autism that remains poorly understood is the differences that may occur in terms of structural language—the form and meaning of language governed by syntax, semantics, and narrative structure—between autistic people of different sexes/genders. Not only is language development a key consideration in the process of diagnosing autism but also better language abilities are positively correlated with improved mental health and improved outcomes for social, academic, and occupational pursuits for autistic people (Howlin et al., 2004; Mayes & Calhoun, 2011). Despite the importance of language, it remains unclear whether structural language skills develop differently in autistic people who are not male. For these reasons, a scoping review of the research on the intersection of language and sex/gender in autism is both timely and critical to understand how researchers are engaging with autistic individuals of different genders and to reconceptualize our approach to diagnostic norms and support needs.

Constructs of sex and gender

The constructs of sex and gender are conceptually distinct from one another (World Health Organization (WHO), 2019). Sex refers to biological and physiological aspects, including the genetics, hormones, and reproductive anatomy associated with female, male, or intersex individuals (WHO, 2019). Gender refers to the sociocultural aspects of identity, encompassing the norms, roles, and experiences associated with identifying as or being perceived as a woman, man, or other gender identity (WHO, 2019). These norms and expected behaviors are ingrained through gendered socialization of children, which begins early and is pervasive in their developmental environment (Fine, 2010; Harris, 2009). For example, based on an infant’s perceived gender, adults provide infants with different toys and physical environments (Pomerleau et al., 1990). Adults differentially interpret characteristics based on the perceived gender of the infant, typifying boys as angry, strong, and physically capable, and girls as afraid, small, soft, and physically incapable (Burnham & Harris, 1992; Condry & Condry, 1976; Mondschein et al., 2000; Rubin et al., 1974). Gender norms and expectations are not limited to neurotypical individuals—all infants are subject to gendered socialization. Just as gendered socialization influences the development of neurotypical children, the process may contribute to the differences in language and autistic characteristics observed in autistic individuals of different genders (Cheslack-Postava & Jordan-Young, 2012). For example, female infants experience more “bids for social engagement” (Cheslack-Postava & Jordan-Young, 2012, p. 1671) in their environment than male infants, which offers autistic girls an early advantage in terms of the parental interactions that promote communication.

Gender diversity in the autistic population

Gender diversity is high in the autistic population; it is not uncommon for autistic people to be transgender, nonbinary, gender-nonconforming, or other marginalized identities (Strang et al., 2020; Walsh et al., 2018; Warrier et al., 2020). Far from assigning a gendered rigidity to autistic traits (i.e. the “extreme male brain theory”; Krahn & Fenton, 2012), it is important to reemphasize that the “female autism phenotype” need not occur only in girls and women but may merely be more common in them (Watts, 2019). However, in Lai and Szatmari’s (2020) recent literature review spanning sex/gender differences in autism, reviewed articles had an overall low likelihood of differentiating whether they were examining sex or gender differences. Furthermore, we do not know to what extent the current research on sex-/gender-related language differences in autism considers the rich gender diversity of the autistic population.

Gendered language differences in neurotypical individuals

Sex/gender differences exist in neurotypical language learners across development. Typically developing girls develop more sophisticated structural language, including semantic, syntactic, and narrative skills, earlier than boys (Adani & Cepanec, 2019). In early childhood, girls’ advantages over boys include faster receptive and expressive lexical development (Bauer et al., 2002; Berglund et al., 2005; Lutchmaya et al., 2002; Zambrana et al., 2012) and production of a greater variety and complexity of syntactic forms (Bouchard et al., 2009; Simonsen et al., 2013). School-age girls and adult women continue to demonstrate superior linguistic performance over boys and men, including verbal fluency and standardized academic measures of reading and writing (Barel & Tzischinsky, 2018; Petersen, 2018).

These differences have been tied to biological factors which indicate a female advantage for language development, including sex-related differences in neurogenetic markers, hormones, and functional organization and activation patterns of the brain (Adani & Cepanec, 2019). However, these language differences are also due to differences in gendered socialization (Fine, 2010), including the linguistic input infants receive. Mothers provide increased verbal stimulation to female infants compared to male infants (M. Page et al., 2010) and respond to vocalizations of female infants more frequently than those of male infants (Johnson et al., 2014). Mothers spend more time engaged in activity and reciprocal conversation-style communication with female than male infants, such as making comments rather than giving instructions (Clearfield & Nelson, 2006). Sociolinguistic studies have also revealed gender differences in later development: for example, women tend to use more polite forms, hedges, fillers, tag questions, verbs, and negation words than men (Holmes, 1995; Lakoff, 1975; Newman et al., 2008). These effects of gendered socialization on language development have been documented extensively among neurotypical samples, but not among autistic people.

Structural language and autism

Structural language is of particular interest in the context of autistic communication for several reasons. While pragmatic language is often discussed in relation to the autistic population, syntactic, semantic, and narrative skills are also critical components of social communication. For autistic people who engage in social camouflaging, their structural language strengths may be a factor in the diagnostic disparities they face, as their communication difficulties or differences may be less evident to clinicians (Cook et al., 2021; Parish-Morris et al., 2017). Research has shown that autistic camouflaging involves adjusting one’s language and communication to appear more neurotypical, such as asking questions, using specific phrases, following conversational scripts (Hull et al., 2017), clarifying speech by rephrasing or using careful wording (Cook et al., 2021), and producing filler words um and uh in gender-normative distributions (Parish-Morris et al., 2017). Although autistic girls and women engage in camouflaging to a greater extent than autistic boys and men (Hull et al., 2020), it is not clear where autistic individuals of other genders fall in this comparison. Research on the linguistic strategies of camouflaging is early, but suggests that when autistic girls and women camouflage, they may be likely to approximate the structural language characteristics of their neurotypical peers. Although there are well-documented differences in the language abilities of neurotypical women and men, little is known about these differences in autistic women and men. Most studies conducted on structural language in autism do not analyze their results according to sex/gender (e.g. Horvath et al., 2018; Kamio et al., 2007; Khetrapal & Thornton, 2017; King & Palikara, 2018) and may consequently miss important differences. An important first step in understanding the differences observed in the autistic phenotypes of men and women is to investigate whether the differences observed in neurotypical women and men are similar to what is observed in autistic people, particularly given the numerous sex/gender differences that have already been shown in other aspects of autistic development (Dean et al., 2014; Lai & Szatmari, 2020; Posserud et al., 2016). Linguistic profiles may represent a dimension of meaningful contrast between these autism presentations. As such, improved analysis of structural language development in autistic individuals of different genders will result in more sophisticated assessment and treatment decisions.

Current study

A scoping review was conducted for the purposes of outlining the emerging research in the area of sex-/gender-related differences in structural language within autism and determining the extent to which such research is inclusive of gender diversity. A systematic review is indicated for questions “addressing the feasibility, appropriateness, meaningfulness, or effectiveness of a certain treatment or practice,” in contrast to a scoping review’s purpose of “identification. . ., mapping, reporting, or discussion of [certain] characteristics/concepts” (Munn et al., 2018, p. 3). A scoping review is an ideal methodology to begin to address this question because scoping reviews are designed to map and interpret the available evidence in emerging fields, as well as “clarify a complex concept and refine subsequent research inquiries” (Levac et al., 2010).

The following research questions were developed: How do studies on this topic define, incorporate, or approach the concept of sex/gender? Is there evidence of a difference in structural language (defined here as syntactic, semantic, and narrative skills) across sex/gender in autism?

Methods

The methodology of this scoping review is based on established frameworks for conducting scoping reviews (Colquhoun et al., 2014; Levac et al., 2010; Tricco et al., 2018). The search terms “(autism) AND (gender OR girls) AND (language OR semantics OR syntax OR narrative)” were used to search five databases: PubMed, Web of Science, PsycInfo, Scopus, and EBSCOhost. The search, occurring on October 6, 2022, resulted in 3315 unique articles, which were compiled and imported into the systematic review management software Covidence.

Two members of the research team, the lead author and an undergraduate in speech and hearing science, independently screened the titles and abstracts of the articles to determine whether they met the inclusion criteria. The undergraduate researcher received training in the coding procedures but remained naïve to the exact research questions. Ninety-six percent of the articles were screened for inclusion criteria by both raters and their reliability was 98%. In instances where the researchers disagreed, the inclusion and exclusion criteria were discussed by the two coders and a third member of the research team (the second author) until consensus was achieved. Of the 3315 articles in the initial screening phase, 3265 were determined not to meet criteria. We assessed the remaining 50 articles in their full text and found 26 ineligible for inclusion. This procedure is summarized in Figure 1.

Figure 1.

PRISMA flow diagram.

To be included in the review, articles needed to involve autistic participants who were not all males: mixed-sex/gender samples and female samples were acceptable. Articles were required to contain quantitative results, separated by sex/gender, pertaining to at least one domain of structural language (syntax, semantics, or narrative discourse). Articles were excluded if they only examined the relatives or caregivers of autistic people, or if the methodology focused on anatomical, genetic, or medical aspects of autism or sex/gender. In addition, articles published prior to 2000 were excluded. Participant age was not used as a criterion. Articles published after December 31, 2021, were not included.

The following information was coded for each article: the researcher’s approach to sex/gender as a variable (i.e. biological/sociocultural-identity, binary/non-binary, vocabulary choices), number of participants of different sexes/genders and neurotypes, mean age of the participants, measure(s) used to assess language domains, and results of the language measures by sex/gender. All variables were coded by two members of the research team and conflicts were resolved through discussion, as with the screening process described above. This data charting procedure was initially calibrated and refined using two articles to ensure consistency with the research questions and purpose of the review and evaluated iteratively thereafter.

Community involvement

Throughout the process of conducting the review, the research team consulted with a small group of stakeholders as representatives of the autistic community. This group comprised four diagnosed autistic women of varying ages living in the Midwest, located through The Ohio State University Nisonger Center, who were invited to serve as consultants. They volunteered to take part in periodic teleconferences, in which they offered firsthand descriptions of their experiences and provided perspectives to help guide both the development of the research questions and the interpretations of the findings. Their impact on the research included confirming the worth of the research questions, anecdotally corroborating the unique experiences of autistic girls with strong language skills, and suggesting future research directions.

Results

Twenty-four articles were included in the final analysis. Fifty percent of the articles (n = 12) were published in 2019 or later, highlighting the emergent nature of this topic. The understudied nature of sex and gender differences in autism is highlighted by the high volume of research on structural language in autism that does not analyze results by sex/gender. One illustration of this contrast is a 10-article research topic in Frontiers in Psychology on structural language and autism, in which none of the articles met criteria for inclusion in this review (Durrleman & Gavarró, 2018). In the discussion, each of the following factors will be reported in turn: approach to sex/gender as a characteristic, participant characteristics, and structural language.

Approach to sex and gender as constructs

With respect to our research question regarding how studies define, incorporate, or approach sex and/or gender, 18 of the 24 articles approached the concept from a position rooted in the biological and binary idea of sex. Five of the 18 articles used consistent language to demonstrate whether they were discussing sex or gender: Asberg et al. (2010) and Lin and Chiang (2014) consistently used “gender,” “boy,” and “girl,” and Demetriou et al. (2021), Lai et al. (2011), and Ludwig (2013) consistently used “sex,” “male,” and “female,” with contextually appropriate usage of “boy” and “girl” when discussing other research about gender. The remaining 13 articles used inconsistent language (i.e. interchangeably using “sex”/”gender” and/or “males-females”/”boys-girls”) or mismatched language (i.e. consistently using “sex” but referring to “boys and girls” or consistently using “gender” but referring to “males and females”). Only four articles explicitly acknowledged the difference between sex and gender, frequently citing the World Health Organization (2019), and all four stated that they intended to focus on biological sex (Boorse et al., 2019; Dillon et al., 2021; Harrop et al., 2020; Song et al., 2021). Dillon et al. (2021) included a parent-report measure of autistic children’s sex/gender concordance (i.e. whether an individual’s gender identity aligned with their sex assigned at birth) and found concordance rates above 98%. Dworzynski et al. (2012) and Oates (2019) expressed an understanding of gendered socialization. Only one article acknowledged sexes or genders beyond the binary (Oates, 2019).

Participant characteristics

Across the articles, the average ages of the participants ranged from 18 months to 27 years. In total, the studies featured 25,681 subjects—4974 autistic females, 18,744 autistic males, 636 nonautistic females, and 1327 nonautistic males. Ten articles directly reported information about the core autism traits of their participants, in the form of Autism Diagnostic Observation Schedule-2 (ADOS-2; Lord et al., 2012) scores, or Autism Spectrum Screening Questionnaire (ASSQ; Kopp & Gillberg, 2011) scores. Two of these 10 articles reported that boys showed significantly more autistic traits than girls (Craig et al., 2020; Harrop et al., 2020), featuring participants with mean ages of 4 and 12.5 years, respectively. One reported higher levels of autistic traits in girls than in boys (Carter et al., 2007) and the remaining seven reported no significant sex/gender differences in autistic trait scores (Asberg et al., 2010; Boorse et al., 2019; Conlon et al., 2019; Demetriou et al., 2021; Immormino, 2016; Song et al., 2021; Sturrock, Marsden, Adams, & Freed, 2020). Thirteen articles simply stated that participants were clinically diagnosed with autism or an autism spectrum disorder, and one relied on participants’ reports of their autism status.

Comparison groups

Twelve articles included only autistic girls/women and autistic boys/men. Nine included a four-way comparison between autistic girls/women, autistic boys/men, nonautistic girls/women, and nonautistic boys/men. Two articles included only autistic girls and nonautistic girls, and one article included all groups except nonautistic boys.

Structural language results

Some articles provided more readily operationalized information about language than others. As such, we categorized findings of syntactic, semantic, and narrative skills according to broad definitions. For example, an article reporting the syntax subscale and semantics subscale scores of the Children’s Communication Checklist-2 (CCC-2; Bishop, 2006; Burton et al., 2020) was analyzed for syntactic and semantic findings. As a less straightforward example, an article measuring age at first word and age at first three-word phrase (Harrop et al., 2020) was considered to contain semantic and syntactic information respectively for these data. Extracted data and primary findings for syntactic, semantic, and narrative skills are presented in Supplementary Tables 1 to 3, respectively. Because articles may have assessed more than one aspect of structural language, they may be listed in more than one table. See Figure 2 for a breakdown of the results across structural language.

Figure 2.

Frequency of findings by group comparison.

Syntax

Seventeen articles assessed syntax (Supplementary material, Table 1). Children’s syntactic skills typically begin to develop around 2 years of age when children begin to produce two-word utterances. Duvall et al. (2020) found no significant differences between 3-year-old autistic girls and autistic boys’ standard language scores. This differs from the findings of Harrop et al. (2020) who examined language complexity and age at diagnosis by gathering parental reports of developmental milestones, such as a child’s age at their first production of a three-word phrase. They found that autistic girls produced three-word phrases significantly earlier than autistic boys, and that age at diagnosis was later for girls than boys. Likewise, when Salomone et al. (2016) surveyed parents about their 5-year-old (range = 4–7) children’s verbal ability (e.g. nonverbal, single words, or complex phrases) and the age at which they received an autism diagnosis they found that for girls, but not boys, complex phrase speech was associated with a later age at diagnosis. Lee (2009) found that autistic girls developed phrase speech significantly later than autistic boys, but there were no differences in the emergence of sentences. Hus et al. (2007), on the other hand, found no significant differences in autistic boys’ and girls’ ages at the first phrase produced. In toddlers, Carter et al. (2007) found that autistic boys significantly outperformed autistic girls on a measure of receptive and expressive language, but the results from Ludwig (2013) showed no significant sex/gender differences on the same assessment. Dworzynski et al.’s (2012) analysis revealed that 3-year-old girls, but not boys, who received autism diagnoses had significantly lower language scores than nondiagnosed peers with similar levels of autistic traits.

There are similarly mixed findings regarding the syntactic skills of early school-age autistic children. Conlon et al. (2019) and Dillon et al. (2021) both investigated the syntactic skills of autistic children with a mean of 8 years of age. Dillon et al. (2021) found that parents of autistic children reported that boys started combining words and using complex phrases at significantly later ages than girls. In contrast, Conlon et al.’s (2019) analysis of language samples of autistic girls and autistic boys found no significant sex/gender differences in the syntactic complexity of the narratives (e.g. use of subordinate clauses or modifiers). This is similar to the findings from Lin and Chiang (2014) who found that there was not a significant sex/gender difference in 7- to 9-year-old children (Lin et al., 2014).

Seven of the articles assessing syntactic skills focused on autistic children with a mean age of 11–13 years. Findings from these research studies were mixed. Four of the studies reported no difference in the syntactic skills of autistic girls and boys: Burton et al. (2020) found no significant differences between autistic girls and nonautistic girls on parent report and direct measures of syntax. Sturrock, Yau, Freed, and Adams (2020) found no significant sex/gender across multiple direct measures of syntax. Kauschke et al. (2016) administered a storytelling task to autistic girls, autistic boys, and nonautistic girls. They found that there was not a difference in mean length of utterance (MLU) or syntactic complexity in the language samples of all three groups. Similarly, a language sample analysis from Immormino (2016) revealed no significant differences in MLU or grammatical complexity among autistic girls and boys.

The other three studies focusing on 11- to 13-year-old children did report differences in the syntactic skills of autistic girls and boys: Song et al. (2021) analyzed pronoun usage within unstructured social conversations with autistic and nonautistic children. They presented a series of findings indicating significant differences across sex/gender and neurotype: while autistic children tend to use fewer plural pronouns than nonautistic children, the pattern of usage differed by sex/gender, with “we” being used most frequently by non-autistic girls, followed equally by nonautistic boys and autistic girls, then autistic boys. The word “they” was used most frequently by autistic girls, followed equally by nonautistic girls and nonautistic boys, then autistic boys. This trend highlights the discrepancy between autistic and nonautistic girls’ pronoun use and demonstrates not only an awareness of social groups by autistic girls but also an awareness of their exclusion from these groups. Although Lin and Chiang (2014) did not find significant differences in the receptive syntactic skills of 7- to 9-year-old children, they did find that 10- to 12-year-old girls diagnosed with Asperger’s Syndrome scored significantly higher than matched boys. Finally, Sturrock, Marsden, Adams, and Freed (2020) found that parent reports of girls’ syntactic skills fell below the girls’ results on the direct assessment. The same pattern did not occur for boys.

Several of the above studies featured small sample subgroups (e.g. autistic girls) of less than 20 participants: Burton et al. (2020), Conlon et al. (2019), Kauschke et al. (2016), Immormino (2016), Song et al. (2021), Sturrock, Marsden, Adams, and Freed (2020), and Sturrock, Yau, Freed, and Adams (2020). Results pertaining to syntax are summarized in Supplementary material Table 1.

Semantic

Twenty-one articles reported results regarding semantic skills (Supplementary material, Table 2). Semantic development begins in infancy with the initial acquisition of receptive and expressive vocabulary. Using a medical history form and the Autism Diagnostic Interview, Revised (ADI-R; Rutter et al., 2003), Harrop et al. (2020) found that autistic girls produced their first word significantly earlier than autistic boys. In contrast, Hus et al. (2007), Lai et al. (2011), and Lee (2009) each found no significant sex/gender differences in the age of first word for autistic children. Of three studies using the same direct measure of expressive and receptive language skills for preschool children (Carter et al., 2007; Duvall et al., 2020; Ludwig, 2013), only one showed a significant effect of gender: autistic boys outperformed autistic girls (Carter et al., 2007). The preschool period typically involves rapid lexical and concept acquisition (Owens, 2016). Craig et al. (2020) found that autistic preschool girls demonstrated more advanced expressive word usage for requesting and other communications than autistic preschool boys. No significant sex/gender differences were observed in receptive language. Finally, within this age group, Dworzynski et al.’s (2012) analysis revealed that girls, but not boys, who received autism diagnoses had significantly lower language scores than nondiagnosed peers with similar levels of autistic traits.

The majority of studies examining semantic skills focused on school-age participants. Vocabulary growth in these years is typically characterized by adding new lexical items, slow-mapping additional information to known words, and reorganizing the lexicon based on an increasingly abstract understanding of words and their relationships (Owens, 2016). Conlon et al.’s (2019) analysis of language samples from 8- to 9-year-old autistic children revealed that autistic girls in the sample used richer and more enhancing vocabulary than autistic boys. Many of the research studies investigating this age range revealed a female advantage in semantic ability. In one study, researchers found no difference in non-autistic children and autistic girls’ (with a mean age of 11 years) use of social category words (e.g. friend, family) during unstructured social conversations; however, social category words were used significantly less often by the autistic boys in the sample (Song et al., 2021). Yet, across most studies, nonautistic girls demonstrate better semantic skills than autistic girls. Goddard et al. (2014) found that verbal fluency was significantly higher in 8- to 16-year girls than boys, regardless of autism status. Burton et al. (2020) found that 7- to 15-year-old autistic girls had significantly lower semantic abilities when they were compared to age-matched nonautistic girls. Asberg et al. (2010), however, did not find a significant difference between autistic and nonautistic 12-year-old girls in terms of their expressive vocabulary. Receptive vocabulary also did not significantly differ among minimally speaking 13-year-old autistic girls and boys (Immormino, 2016).

Sturrock, Yau, Freed, and Adams (2020), who conducted several assessments of semantic abilities, found that among their sample of children with a mean age of 11, nonautistic girls performed significantly better than all other groups, followed by nonautistic boys, then autistic girls, and finally, autistic boys. They also observed that girls scored significantly higher than boys on measures of emotional vocabulary, regardless of autism status. With this same sample of children, Sturrock, Marsden, Adams, and Freed (2020) compared these direct assessment measures to parental reports of their autistic children’s semantic skills. They observed that parents rated girls lower than boys on the CCC-2 (Bishop, 2006), and that, for girls only, the parent reports of semantic skills fell below the results of the direct assessment. Kauschke et al. (2016) found that 8- to 19-year-old nonautistic girls used significantly more emotional words in a storytelling task than the autistic participants. In language samples from autistic adolescents, analyzed by Oates (2019), girls produced significantly more first-person singular pronouns and negative emotion words, while boys produced significantly more modifiers. The overall female advantage in semantic ability seen in the school-age years continues into adulthood: Within a semantic fluency task, women produced significantly more associated words than men, regardless of autism status (Demetriou et al., 2021).

Several of the above studies featured small sample subgroups (e.g. autistic girls) of less than 20 participants: Burton et al. (2020), Conlon et al. (2019), Goddard et al. (2014), Kauschke et al. (2016), Immormino (2016), Song et al. (2021), Sturrock, Marsden, Adams, and Freed (2020), and Sturrock, Yau, Freed, and Adams (2020). Semantic results are summarized in Supplementary material Table 2.

Narrative

Six articles reported findings related to narrative skills (Supplementary material, Table 3). Narrative skills typically emerge around 3–5 years of age and become more sophisticated and coherent in the early school years. Conlon et al. (2019) observed that 8- to 9-year-old autistic girls incorporated significantly more salient story elements and descriptions of character intentions than did autistic boys. Boorse et al. (2019) found that autistic children (with a mean age of 10 years) used significantly more nouns in their narratives than the nonautistic children, and that autistic girls incorporated significantly more cognitive process words (e.g. think, know, wonder) with respect to story characters than autistic boys. Sturrock, Yau, Freed, and Adams (2020) found no significant sex/gender differences in narrative length, complexity, causal markers, or temporal markers in a sample of autistic children with a mean age of 11 years. In comparing 7- to 15-year-old autistic girls to nonautistic girls, Burton et al. (2020) found that autistic girls scored significantly lower on a narrative coherence subscale than non-autistic girls. Goddard et al. (2014) elicited narratives of personal memories from autistic and non-autistic children between 8 and 16 years old and noted that girls included significantly more details and emotions than boys, regardless of autism status. Kauschke et al. (2016) examined the narratives of 8- to 19-year-old autistic children and found that while narrative competence (e.g. length, coherence) did not differ significantly across groups, autistic girls referenced characters’ internal states (e.g. motivation) more often than autistic boys. These results are summarized in Supplementary material Table 3.

Discussion

This scoping review aimed to provide a comprehensive overview of sex-/gender-related differences in structural language within autism, and to determine the extent to which such research is inclusive of gender diversity. Of the thousands of articles initially screened for this study, 24 met the criteria for inclusion. Seventy percent of the articles (n = 17) reported at least one finding that set autistic girls apart from comparison groups in terms of structural language, whether the comparison groups were autistic boys, nonautistic girls, or both. The articles’ approaches to sex and gender as constructs, as well as each of the three aspects of structural language, are discussed in turn, followed by a more global discussion.

Approach to sex and gender as constructs

The results about the studies’ approaches to sex and gender as constructs revealed an area of potential growth for the field, with most of the articles neither acknowledging explicitly that sex and gender are distinct constructs nor displaying a consistent understanding of the constructs through their language choices. Only one (Oates, 2019) acknowledged nonbinary individuals or other marginalized genders. While recruiting gender-diverse samples may be difficult methodologically, it should be strongly considered given that language differences stem from both biological and societal forces (Adani & Cepanec, 2019; Clearfield & Nelson, 2006; M. Page et al., 2010), and given the considerable overlap between neurodiversity and gender diversity (Warrier et al., 2020). These findings show that not only is current research in this area not inclusive with regard to gender in a population that is highly gender diverse but also that many researchers are mishandling the constructs of sex and gender. While the evolution of sex and gender terminology is certainly ongoing, the fundamental distinction between the two constructs has been established for decades (Connell, 1995; Lorber, 1994; Messner, 2000; Stoller, 1984; West & Zimmerman, 1987). Awareness of nonbinary gender identity has increased substantially within the last decade. This scoping review has revealed that studies from earlier in the 21st century, as well as more contemporary studies, tend to lack nonbinary autistic participants. While this omission is understandable for earlier research, it is an important observation to recognize the potential limitations of such research given our current awareness of the autistic population as highly gender diverse. Researchers in this area need to be aware of and make use of evolving terminology, both to improve the clarity of their message and to prevent harmful misinterpretations. The issues of gender diversity must be carefully considered moving forward in the field of autism, as we cannot reliably assume that a given individual’s profile of linguistic strengths and needs will align with their sex assigned at birth. Therefore, if phenotype-specific test norms are developed, selecting which to use clinically with a given individual should be a flexible process

Syntax

The findings regarding syntactic skills are mixed. Seven of the 17 articles that assessed syntax found significant strengths in the syntactic skills of autistic girls as compared to autistic boys (Dillon et al., 2021; Dworzynski et al., 2012; Harrop et al., 2020; Lin & Chiang, 2014; Salomone et al., 2016; Song et al., 2021; Sturrock, Marsden, Adams, & Freed, 2020). Together, these articles indicate that autistic girls are more linguistically advanced than autistic boys in early childhood, and for girls, more complex language is correlated with later ages of diagnosis (Dworzynski et al., 2012; Harrop et al., 2020; Salomone et al., 2016). Yet, this sex/gender difference finding was not consistent across research articles. Multiple articles found that autistic girls did not differ significantly from autistic boys in their syntactic skills (Conlon et al., 2019; Duvall et al., 2020; Hus et al., 2007; Immormino, 2016; Kauschke et al., 2016; Lin & Chiang, 2014; Ludwig, 2013; Sturrock, Yau, Freed, & Adams, 2020). Two studies offered evidence of autistic boys outperforming autistic girls (Carter et al., 2007; Lee, 2009). Conflicting results were also observed when autistic girls were compared to nonautistic girls, including studies involving formal assessments and naturalistic language (Burton et al., 2020; Song et al., 2021).

This collection of articles presents inconsistent results as to whether autistic girls demonstrate distinct syntactic abilities compared with autistic boys or nonautistic girls. Not only did each study measure slightly different attributes (e.g. MLU, pronoun usage, first use of phrase speech), but they also incorporated a wide variety of assessments, precluding broad interpretations. In addition, the use of the same participants in both Sturrock, Yau, Freed, and Adams (2020) and Sturrock, Marsden, Adams, and Freed (2020) shows that the outcomes (i.e. performance of autistic girls relative to autistic boys and nonautistic girls) are at least partially dependent on the assessments used to evaluate skills, as differences between autistic girls and autistic boys were seen in parent-reported skills but not in directly assessed skills (Sturrock, Marsden, Adams, & Freed, 2020; Sturrock, Yau, Freed, & Adams, 2020). There is no clear-cut trend to explain the source of the inconsistency. The included studies comprise a wide variety of procedures and materials; however, neither participant age, language measure/assessment, nor a component of syntax being examined accounts for the inconsistent findings across articles. For example, of the articles measuring MLU and grammatical complexity in school-age autistic children, two found no gender differences (Immormino, 2016; Kauschke et al., 2016) and one found girls using more complexity than boys (Conlon et al., 2019). Patterns of results also differed across articles that examined parental reports of early developmental milestones related to syntax. For these reasons, overall conclusions about syntax remain elusive. Future research may expand our understanding of this topic by assessing a battery of syntactic abilities among autistic and nonautistic participants of multiple genders and various age ranges.

Semantics

The findings on semantic skills are similarly contradictory. One article found autistic boys surpassing autistic girls in language measures (Carter et al., 2007), but multiple articles determined that autistic girls had stronger expressive vocabularies than autistic boys (Conlon et al., 2019; Craig et al., 2020; Demetriou et al., 2021; Goddard et al., 2014; Harrop et al., 2020; Song et al., 2021; Sturrock, Yau, Freed, & Adams, 2020) or used a different pattern of word types than autistic boys (Oates, 2019). Of note, Sturrock, Yau, Freed, and Adams (2020) showed that autistic girls’ semantic skills were stronger than those of autistic boys using several direct assessments, while Sturrock, Marsden, Adams, and Freed (2020) found that the semantic skills of the same sample of autistic girls were underestimated by their parents on the CCC-2 (Bishop, 2006), and received lower semantic ratings from their parents than did autistic boys.

Although many articles observed a difference in the semantic abilities of autistic girls and autistic boys, others did not (Duvall et al., 2020; Hus et al., 2007; Immormino, 2016; Lai et al., 2011; Lee, 2009; Ludwig, 2013). It is worthwhile to note that articles published more recently were overall more likely to demonstrate a semantic advantage among autistic girls as compared to autistic boys. This pattern may represent advancement from earlier research that often observed autistic boys outperforming autistic girls due to the “underrepresentation of higher-functioning females” (Duvall et al., 2020, p. 1782). This inconsistency further illuminates the need for additional research in this area.

While autistic girls tend to have higher-level semantic skills than autistic boys, they also tend to have equivalent or lower semantic skills than their nonautistic same-sex/gender peers (Asberg et al., 2010; Burton et al., 2020; Kauschke et al., 2016). However, a more complex picture emerges in articles comparing both sexes/genders and neurotypes. For example, regardless of autism status, girls’ emotional word usage and verbal fluency were stronger than those of autistic and nonautistic boys’ (Demetriou et al., 2021; Goddard et al., 2014; Song et al., 2021; Sturrock, Yau, Freed, & Adams, 2020). That is, these skills were roughly equivalent across neurotypes within same-sex/gender groups, with girls collectively outperforming boys. Altogether, autistic girls appear to demonstrate stronger semantic abilities than those demonstrated by autistic boys, which may play a key role in allowing autistic girls to blend in with their neurotypical peers and contribute to the issue of underdiagnosis.

Narrative

In terms of narrative skills, although the articles measure a range of related but distinct proficiencies, girls demonstrated more advanced abilities boys (Boorse et al., 2019; Conlon et al., 2019; Goddard et al., 2014; Kauschke et al., 2016). When comparing within sex/gender, autistic girls scored lower than nonautistic girls on narrative measures in the CCC-2 (Bishop, 2006; Burton et al., 2020). Only Sturrock, Yau, Freed, and Adams (2020) found no differences in the narrative domain. Indeed, these authors expressed surprise at their narrative findings and speculated that increasing statistical power with a larger sample might lead to a different conclusion, although their sample is comparable to the other articles addressing narrative skills. Another possible source of the discrepancy is that most of the other studies utilized a narrative task that originated within a standardized assessment, while Sturrock, Yau, Freed, and Adams’s (2020) storytelling task did not.

Intersecting effects of sex/gender and autism on structural language

The findings from this scoping review indicate that semantic and narrative skills appeared to be more susceptible than syntactic skills to the influence of sex/gender, wherein autistic girls outperform autistic boys. We hypothesize that this pattern may reflect the influence of gendered socialization on language development. For example, infant girls are exposed to more language from their mothers (Clearfield & Nelson, 2006; M. Page et al., 2010), and school-age girls participate in more conversation-based social interactions with their peers than boys do (Blatchford et al., 2003). Perhaps, such instances of gendered socialization have a more profound impact on the development of semantic and narrative skills than on syntactic skills. When children acquire language, neither parents nor children tend to focus on correcting the details of grammar as much as they do on vocabulary (Sedivy, 2014), suggesting that different aspects of structural language acquisition may be associated with different types of social interactions. A complementary explanation draws upon the nature of autistic camouflaging, such that autistic girls may find it easier or more effective to camouflage by adopting others’ vocabulary choices and storytelling styles than by imitating syntactic forms. In this way, we may think of camouflaging as a form of codeswitching, wherein a speaker alternates between distinct forms of communication depending on the context (Morrison, 2017). These interpretations are broadly consistent with the experiences of our autistic women stakeholders, who reported varying linguistic and communication challenges in their lives and affirmed that they engage in social camouflaging strategies to appear more neurotypical, particularly in high-stakes contexts such as job interviews.

Almost none of the 24 articles reported findings of poorer performance for girls than boys, soundly rejecting the long-standing idea that autistic girls are necessarily more negatively impacted than boys (Fombonne, 2009). The few instances of a difference in this direction came from Carter et al. (2007), Lee (2009), and Sturrock, Marsden, Adams, and Freed (2020). Regarding the latter, in the parent-report component of the semantic and syntactic skill assessment, parents rated girls’ skills lower than they did boys’, but this result was not corroborated by direct assessment of the skills (Sturrock, Yau, Freed, & Adams, 2020). Taken altogether, the significant effects for structural language skills aggregated here create a loose hierarchy in terms of sex/gender and autism, where being a girl confers an advantage to linguistic development and being autistic confers a disadvantage. The extreme points on the hierarchy are consistent: nonautistic girls have the strongest skills, and autistic boys have the weakest. However, the remaining two groups are less fixed: in some studies, autistic girls are stronger than nonautistic boys, in some the reverse, and in some they are equal. This pattern is consistent with the literature about the advantage that girls experience in developing language (Adani & Cepanec, 2019), but it further suggests that this gendered advantage may have a greater effect on certain language skills than autism status. In this way, autistic children are best compared to their same-sex/gender nonautistic peers to optimally understand the language difficulties associated with autism. Comparing autistic girls to nonautistic girls is more likely to reveal areas of linguistic difference and potential targets of intervention.

Autistic girls are less likely to share the same quality and magnitude of structural language difficulties as autistic boys, and in such a comparison, girls may erroneously appear to be without challenges. As such, diagnostic tools normed primarily on boys should be used critically with autistic girls. This is a key takeaway given that the current gold-standard diagnostic tools are biased toward identifying boys (Navarro-Pardo et al., 2021); for example, 80% of the sample used to develop the revised algorithm for Module 4 of the ADOS-2 (Lord et al., 2012) were individuals identified as male (Hus & Lord, 2014).

Limitations

Because research on sex/gender differences in structural language among autistic individuals is scarce, several of the included articles had primary aims unrelated to the precise issue at hand; that is, the relevant results were often indirect outcomes of the main focus. For this reason, it was difficult to integrate the pertinent information across these disjointed sources. In addition, a limitation of a scoping review is that articles cannot be gathered indefinitely, with the potential consequence of excluding the latest relevant articles. This is particularly troublesome for a research area like this one, which is seeing a recent increase in publications explicitly focused on this topic.

While this scoping review has illuminated some thought-provoking developments, more research is needed on this topic for definitive answers. It is encouraging that 24 studies, encompassing such a wide range of language measures and assessment styles, provided a relatively shared outcome in terms of the presence and direction of significant effects. Yet, this methodological diversity also renders it more difficult to draw coherent and comprehensive conclusions. For example, there were discrepancies according to assessment style in the findings of Sturrock, Yau, Freed, and Adams (2020) and Sturrock, Marsden, Adams, and Freed (2020), such that the same participants were found to have no significant sex/gender differences or significant differences in opposite directions depending on the assessment style used. Finding such discrepancies was the aim of Sturrock, Marsden, Adams, and Freed (2020), so this is not intended as criticism of their work. On the contrary, it highlights that the scoping review results overall must be interpreted with caution due to the myriad of assessments used in the collected articles. Future research may be directed toward determining the appropriateness of various assessments for this topic, as well as toward building a more consistent body of evidence to achieve a more conclusive understanding. Furthermore, the between sex/gender comparisons themselves within several of the included studies must be interpreted with caution because the samples of autistic girls were small relative to autistic boys and may be underpowered.

There are several avenues for next steps in this line of inquiry. Given the high volume of studies on structural language and autism that have not analyzed their data by sex/gender, researchers may request the data from the authors of these studies to conduct a meta-analysis. Another important consideration is that the overall clinical sample of autistic girls/women is broader than the typical research sample of autistic girls/women. Due to the historical underdiagnosis of autistic girls/women, those who received a diagnosis were more likely to have co-occurring conditions than autistic boys (Dworzynski et al., 2012; Giarelli et al., 2010; Wing, 1981). While autism research predominately includes people with high nonverbal abilities (i.e. without intellectual disabilities), it also tends to exclude autistic girls/women with subtler autistic traits: Studies that involve screening potential participants to confirm autism status tend to disproportionately exclude clinically diagnosed autistic girls/women, especially when using the ADOS for this purpose (D’Mello et al., 2022). Of the 24 studies included in this review, 12 relied on confirmatory assessments and 12 relied on clinical diagnoses. In addition, more autism and language research is sorely needed that is inclusive of gender diversity. The results gathered and summarized here represent a starting place to improve our understanding of sex/gender, language, and autism, but the exclusion of nonbinary identities signifies that there is more to be learned.

Conclusion

The primary conclusion of this scoping review is the need for additional research to expand and clarify these results. This body of literature remains underdeveloped, despite having high potential for new insights into the nature of sex/gender-autism interactions, language development in autism, linguistic camouflaging, and future best practices for research designs and clinical tools. One recommendation following this study is that a standard practice within autism research should be to recruit sex- and gender-diverse participants and disaggregate data accordingly, as this practice can provide important insights that would not be available otherwise. Researchers considering their study designs should also strive to compare autistic girls’ development and skills to nonautistic girls, rather than only comparing to autistic or nonautistic boys. More generally, it is advised that if autistic people are to be compared to nonautistic people, they should be compared to their same-sex/gender peers. Following this principle, the development of sex-/gender-based norms for diagnostic measures may be appropriate, as may sex/gender-aware communication support measures. Finally, broader awareness of gender diversity both as a concept and as a prevalent feature of the autistic population is essential for researchers to continue learning about sex/gender interactions in autism.

Supplemental Material

sj-docx-1-aut-10.1177_13623613221151095 – Supplemental material for Intersecting effects of sex/gender and autism on structural language: A scoping review

Supplemental material, sj-docx-1-aut-10.1177_13623613221151095 for Intersecting effects of sex/gender and autism on structural language: A scoping review by Morgan Oates and Allison Bean in Autism

Footnotes

Acknowledgements

We would like to acknowledge the autistic women stakeholders, including Briana Miller and three others, who helped guide our research questions and interpretation. We would also like to acknowledge Rachel Caplan, who assisted with the coding.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Morgan Oates

Supplemental material

Supplemental material for this article is available online.

Notes

References

Adani

Cepanec

(2019). Sex differences in early communication development: Behavioral and neurobiological indicators of more vulnerable communication system development in boys. Croatian Medical Journal, 60(2), 141–149. https://doi.org/10.3325/cmj.2019.60.141

*Asberg

Kopp

Berg-Kelly

Gillberg

(2010). Reading comprehension, word decoding and spelling in girls with autism spectrum disorders (ASD) or attention-deficit/hyperactivity disorder (AD/HD): Performance and predictors. International Journal of Language and Communication Disorders, 45(1), 61–71.

Barel

Tzischinsky

(2018). Age and sex differences in verbal and visuospatial abilities. Advances in Cognitive Psychology, 14(2), 51–61. https://doi.org/10.5709/acp-0238-x

Bargiela

Steward

Mandy

(2016). The experiences of late-diagnosed women with Autism Spectrum Conditions: An investigation of the female autism phenotype. Journal of Autism and Developmental Disorders, 46(10), 3281–3294. https://doi.org/10.1007/s10803-016-2872-8

Bauer

D. J.

Goldfield

B. A.

Reznick

J. S.

(2002). Alternative approaches to analyzing individual differences in the rate of early vocabulary development. Applied Psycholinguistics, 23(3), 313–335. https://doi.org/10.1017/S0142716402003016

Berglund

Ericksson

Westerlund

(2005). Communicative skills in relation to gender, birth order, childcare and socioeconomic status in 18-month-old children. Scandinavian Journal of Psychology, 46(6), 485–491. https://doi.org/10.1111/j.1467-9450.2005.00480.x

Bishop

D. V.

(2006). Children’s Communication Checklist–2 (United States ed.). The Psychological Corporation.

Blatchford

Baines

Pellegrini

(2003). The social context of school playground games: Sex and ethnic differences, and changes over time after entry to junior school. British Journal of Developmental Psychology, 21, 481–505. https://doi.org/10.1348/026151003322535183

*Boorse

Cola

Plate

Yankowitz

Pandey

Schultz

R. T.

Parish-Morris

(2019). Linguistic markers of autism in girls: Evidence of a “blended phenotype” during storytelling. Molecular Autism, 10, 14. https://doi.org/10.1186/s13229-019-0268-2

10.

Botha

Hanlon

Williams

G. L.

(2021). Does language matter? Identity-first versus person-first language use in autism research: A response to Vivanti. Journal of Autism and Developmental Disorders. Advance online publication. https://doi.org/10.1007/s10803-020-04858-w

11.

Bouchard

Trudeau

Sutton

Bourdreault

Deneault

(2009). Gender differences in language development in French Canadian children between 8 and 30 months of age. Applied Psycholinguistics, 30(4), 685–707. https://doi.org/10.1017/S0142716409990075

12.

Burnham

D. K.

Harris

M. B.

(1992). Effects of real gender and labeled gender on adults’ perceptions of infants. Journal of Genetic Psychology, 153(2), 165–183. https://doi.org/10.1080/00221325.1992.10753711

13.

*Burton

J. M.

Creaghead

N. A.

Silbert

Breit-Smith

Duncan

A. W.

Grether

S. M.

(2020). Social communication and structural language of girls with high-functioning autism spectrum disorder. Language, Speech, and Hearing Services in Schools, 51(4), 1139–1155. https://doi.org/10.1044/2020_LSHSS-20-00004

14.

*Carter

A. S.

Black

D. O.

Tewani

Connolly

C. E.

Kadlec

M. B.

Tager-Flusberg

(2007). Sex differences in toddlers with autism spectrum disorders. Journal of Autism and Developmental Disorders, 36, 86–97.

15.

Cheslack-Postava

Jordan-Young

R. M.

(2012). Autism spectrum disorders: Toward a gendered embodiment model. Social Science & Medicine, 74(11), 1667–1674. https://doi.org/10.1016/j.socscimed.2011.06.013

16.

Clearfield

M. W.

Nelson

N. M.

(2006). Sex differences in mothers’ speech and play behavior with 6-, 9-, and 14-month-old infants. Sex Roles: A Journal of Research, 54(1–2), 127–137. https://doi.org/10.1007/s11199-005-8874-1

17.

Colquhoun

H. L.

Levac

O’Brien

K. K.

Straus

Tricco

A. C.

Perrier

Kastner

Moher

(2014). Scoping reviews: Time for clarity in definition, methods, and reporting. Journal of Clinical Epidemiology, 67, 1291–1294. http://doi.org/10.1016/j.jclinepi.2014.03.013

18.

Condry

(1976). Sex differences: A study of the eye of the beholder. Child Development, 47(3), 812–819.

19.

*Conlon

Volden

Smith

I. M.

Duku

Zwaigenbaum

Waddell

Szatmari

Mirenda

Vaillancourt

Bennett

Georgiades

Elsabbagh

Ungar

W. J.

(2019). Gender differences in pragmatic communication in school-aged children with Autism Spectrum Disorder (ASD). Journal of Autism and Developmental Disorders, 49(5), 1937–1948. https://doi.org/10.1007/s10803-018-03873-2

20.

Connell

R. W.

(1995). Masculinities. University of California Press.

21.

Cook

Crane

Hull

Bourne

Mandy

(2021). Self-reported camouflaging behaviours used by autistic adults during everyday social interactions. Autism, 26(2), 1–16. https://doi.org/10.1177/13623613211026754

22.

Craig

Crippa

De Giacomo

Ruggiero

Rizzato

Lorenzo

Fanizza

Margari

Trabacca

(2020). Differences in developmental functioning profiles between male and female preschoolers children with Autism Spectrum Disorder. Autism Research, 13(9), 1537–1547. https://doi.org/10.1002/aur.2305

23.

Dean

Kasari

Shih

Frankel

Whitney

Orlich

Landa

King

Lord

Harwood

(2014). The peer relationships of girls with ASD at school: Comparison to boys and girls with and without ASD. Journal of Child Psychology and Psychiatry, 55(11), 1218–1225. https://doi.org/10.1111/jcpp.12242

24.

*Demetriou

E. A.

Pepper

K. L.

Park

S. H.

Pellicano

Song

Y. J. C.

Naismith

S. L.

Hickie

I. B.

Thomas

E. E.

Guastella

A. J.

(2021). Autism spectrum disorder: An examination of sex differences in neuropsychological and self-report measures of executive and non-executive cognitive function. Autism, 25(8), 2223–2237. https://doi.org/10.1177/13623613211014991

25.

*Dillon

E. F.

Kanne

Landa

R. J.

Annett

Bernier

Bradley

Carpenter

Kim

S. H.

Parish-Morris

Schultz

Wodka

E. L.

Wodka

E. L.

, & SPARK Consortium. (2021). Sex differences in autism: Examining intrinsic and extrinsic factors in children and adolescents enrolled in a national ASD cohort. Journal of Autism and Developmental Disorders. Advance online publication. https://doi.org/10.1007/s10803-021-05385-y

26.

D’Mello

A. M.

Frosch

I. R.

C. E.

Cardinaux

A. L.

Gabrieli

J. D. E.

(2022). Exclusion of females in autism research: Empirical evidence for a “leaky” recruitment-to-research pipeline. Autism Research, 15(10), 1929–1940. https://doi.org/10.1002/aur.2795

27.

Durrleman

Gavarró

(2018). Editorial: Investigating grammar in Autism Spectrum Disorders. Frontiers in Psychology, 9, Article 1004. https://www.frontiersin.org/articles/10.3389/fpsyg.2018.01004

28.

*Duvall

S. W.

Huang-Storms

Presmanes Hill

Myers

Fombonne

(2020). No sex differences in cognitive ability in young children with Autism Spectrum Disorder. Journal of Autism and Developmental Disorders, 50(5), 1770–1785. https://doi.org/10.1007/s10803-019-03933-1

29.

*Dworzynski

Ronald

Bolton

Happé

(2012). How different are girls and boys above and below the diagnostic threshold for autism spectrum disorders? Journal of the American Academy of Child and Adolescent Psychiatry, 51(8), 788–797. https://doi.org/10.1016/j.jaac.2012.05.018

30.

Fine

(2010). Delusions of gender: How our minds, society, and neurosexism create difference. W.W. Norton.

31.

Fombonne

(2009). Epidemiology of pervasive developmental disorders. Pediatric Research, 65(6), 591–598. https://doi.org/10.1203/PDR.0b013e31819e7203

32.

Giarelli

Wiggins

L. D.

Rice

C. E.

Levy

S. E.

Kirby

R. S.

Pinto-Martin

Mandell

(2010). Sex differences in the evaluation and diagnosis of autism spectrum disorders among children. Disability and Health Journal, 3(2), 107–116. https://doi.org/10.1016/j.dhjo.2009.07.001

33.

*Goddard

Dritschel

Howlin

(2014). A preliminary study of gender differences in autobiographical memory in children with an Autism Spectrum Disorder. Journal of Autism and Developmental Disorders, 44(9), 2087–2095. https://doi.org/10.1007/s10803014-2109-7

34.

Halladay

A. K.

Bishop

Constantino

J. N.

Daniels

A. M.

Koenig

Palmer

Messinger

Pelphrey

Sanders

S. J.

Singer

A. T.

Taylor

J. L.

Szatmari

(2015). Sex and gender differences in autism spectrum disorder: Summarizing evidence gaps and identifying emerging areas of priority. Molecular Autism, 6, 36. https://doi.org/10.1186/s13229-015-0019-y

35.

Haney

(2016). Autism, females, and the DSM-5: Gender bias in autism diagnosis. Social Work in Mental Health, 14(4), 396–407. https://doi.org/10.1080/15332985.2015.1031858

36.

Harris

(2009). Gender as soft assembly. Routledge/Taylor & Francis Group.

37.

*Harrop

Libsack

Bernier

Dapretto

Jack

McPartland

J. C.

Van Horn

J. D.

Webb

S. J.

Pelphrey

, & The GENDAAR Consortium. (2020). Do biological sex and early developmental milestones predict the age of first concerns and eventual diagnosis in Autism Spectrum Disorder? Autism Research, 14(1), 156–168. https://doi.org/10.1002/aur.2446

38.

Holmes

(1995). Women, men, and politeness. Longman.

39.

Horvath

McDermott

Reilly

Arunachalam

(2018). Acquisition of verb meaning from syntactic distribution in preschoolers with autism spectrum disorder. Language, Speech, and Hearing Services in Schools, 49(Suppl. 3), 668–680. https://doi.org/10.1044/2018_LSHSS-STLT1-17-0126

40.

Howlin

Goode

Hutton

Rutter

(2004). Adult outcome for children with autism. Journal of Child Psychology and Psychiatry, 45(2), 212–229. https://doi.org/10.1111/j.1469-7610.2004.00215.x

41.

Hull

Lai

M.-C.

Baron-Cohen

Allison

Smith

Petrides

Mandy

(2020). Gender differences in self-reported camouflaging in autistic and non-autistic adults. Autism, 24(2), 352–363. https://doi.org/10.1177/1362361319864804

42.

Hull

Petrides

K. V.

Allison

Smith

Baron-Cohen

Lai

M. C.

Mandy

(2017). “Putting on my best normal”: Social camouflaging in adults with autism spectrum conditions. Journal of Autism and Developmental Disorders, 47, 2519–2534. https://doi.org/10.1007/s10803-017-3166-5

43.

Hus

Lord

(2014). The autism diagnostic observation schedule, module 4: Revised algorithm and standardized severity scores. Journal of Autism and Developmental Disorders, 44, 1996–2012. https://doi.org/10.1007/s10803-014-2080-3

44.

*Hus

Pickles

Cook

E. H.

Risi

Lord

(2007). Using the Autism Diagnostic Interview—Revised to increase phenotypic homogeneity in genetic studies of autism. Biological Psychiatry, 61(4), 438–448.

45.

*Immormino

(2016). Sex differences in minimally verbal children and adolescents with autism [Unpublished master’s thesis, Boston University].

46.

Johnson

Caskey

Rand

Tucker

Vohr

(2014). Gender differences in adult-infant communication in the first months of life. Pediatrics, 134(6), e1603–e1610. https://doi.org/10.1542/peds.2013-4289

47.

Kamio

Robins

Kelley

Swainson

Fein

(2007). Atypical lexical/semantic processing in high-functioning autism spectrum disorders without early language delay. Journal of Autism and Developmental Disorders, 37, 1116–1122. https://doi.org/10.1007/s10803-006-0254-3

48.

*Kauschke

van der Beek

Kamp-Becker

(2016). Narratives of girls and boys with Autism Spectrum Disorders: Gender differences in narrative competence and internal state language. Journal of Autism and Developmental Disorders, 46(3), 840–852. https://doi.org/10.1007/s10803-015-2620-5

49.

Khetrapal

Thornton

(2017). C-command in the grammars of children with high functioning autism. Frontiers in Psychology, 8, Article 402. https://doi.org/10.3389/fpsyg.2017.00402

50.

King

Palikara

(2018). Assessing language skills in adolescents with autism spectrum disorder. Child Language Teaching and Therapy, 34(2), 101–113. https://doi.org/10.1177/0265659018780968

51.

Kopp

Gillberg

(2011). The Autism Spectrum Screening Questionnaire (ASSQ)-Revised Extended Version (ASSQ-REV): An instrument for better capturing the autism phenotype in girls? A preliminary study involving 191 clinical cases and community controls. Research in Developmental Disabilities, 32(6), 2875–2888. https://doi.org/10.1016/j.ridd.2011.05.017

52.

Krahn

T. M.

Fenton

(2012). The extreme male brain theory of autism and the potential adverse effects for boys and girls with autism. Journal of Bioethical Inquiry, 9, 93–103. https://doi.org/10.1007/s11673-011-9350-y

53.

*Lai

M. C.

Lombardo

M. V.

Pasco

Ruigrok

A. N. V.

Wheelwright

S. J.

Sadek

S. J.

Chakrabarti

MRC AIMS Consortium, & Baron-Cohen

(2011). A behavioral comparison of male and female adults with high functioning autism spectrum conditions. PLOS ONE, 6(6), Article e20835.

54.

Lai

M. C.

Szatmari

(2020). Sex and gender impacts on the behavioural presentation and recognition of autism. Current Opinion in Psychiatry, 33, 117–123. https://doi.org/10.1097/YCO.0000000000000575

55.

Lakoff

(1975). Language and woman’s place. Language and Society, 2, 45–79.

56.

*Lee

H. J.

(2009). Gender differences in adolescents with Asperger syndrome [Doctoral dissertation, University of Kansas]. ProQuest Dissertations Publishing. (Publication No. 3337115)

57.

Levac

Colquhoun

H. L.

O’Brien

K. K.

(2010). Scoping studies: Advancing the methodology. Implementation Science, 5(1), Article 69.

58.

*Lin

Y.-H.

Chiang

H.-M.

(2014). Language comprehension of children with Asperger’s disorder and children with autistic disorder. Research in Autism Spectrum Disorders, 8(7), 767–774. https://doi.org/10.1016/j.rasd.2014.03.018

59.

Lin

Y.-H.

Tseng

C.-H.

Y.-Y.

(2014). Mandarin token test examiner’s manual. Psychological Publishing.

60.

Lockwood Estrin

Milner

Spain

Happé

Colvert

(2021). Barriers to autism spectrum disorder diagnosis for young women and girls: A systematic review. Review Journal of Autism and Developmental Disorders, 8, 454–470. https://doi.org/10.1007/s40489-020-00225-8

61.

Lorber

(1994). Paradoxes of gender. Yale University Press.

62.

Lord

Rutter

DiLavore

Risi

Gotham

Bishop

S. L.

(2012). Autism diagnostic observation schedule (2nd ed.). Western Psychological Services.

63.

*Ludwig

(2013). Sex specific behavioral profiles in toddlers at risk for Autism Spectrum Disorders (ASD) [Unpublished master’s thesis, University of Georgia].

64.

Lutchmaya

Baron-Cohen

Raggatt

(2002). Foetal testosterone and vocabulary size in 18 and 24 month old infants. Infant Behavior and Development, 24, 418–424. https://doi.org/10.1016/S0163-6383(02)00087-5

65.

Mayes

S. D.

Calhoun

S. L.

(2011). Impact of IQ, age, SES, gender, and race on autistic symptoms. Research in Autism Spectrum Disorders, 5(2), 749–757. https://doi.org/10.1016/j.rasd.2010.09.002

66.

Messner

M. A.

(2000). Barbie girls versus sea monsters: Children constructing gender. Gender & Society, 4(6), 765–784.

67.

Mondschein

E. R.

Adolph

K. E.

Tamis-LeMonda

C. S.

(2000). Gender bias in mothers’ expectations about infant crawling. Journal of Experimental Child Psychology, 77(4), 304–316. https://doi.org/10.1006/jecp.2000.2597

68.

Morrison

C. D.

(2017, May 30). Code-switching. Encyclopedia Britannica. https://www.britannica.com/topic/code-switching

69.

Munn

Peters

M. D. J.

Stern

Tufanaru

McArthur

Aromataris

(2018). Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach. BMC Medical Research Methodology, 18(1), Article 143. https://doi.org/10.1186/s12874-018-0611-x

70.

Navarro-Pardo

López-Ramón

Alonso-Esteban

Alcantud-Marín

(2021). Diagnostic tools for autism spectrum disorders by gender: Analysis of current status and future lines. Children, 8(4), 262. https://doi.org/10.3390/children8040262

71.

Newman

M. L.

Groom

C. J.

Handelman

L. D.

Pennebaker

J. W.

(2008). Gender differences in language use: An analysis of 14,000 text samples. Discourse Processes, 45(3), 211–236. https://doi.org/10.1080/01638530802073712

72.

*Oates

(2019). Gender differences in linguistic features in an online forum for adolescents with autism spectrum disorder [Unpublished master’s thesis, The Ohio State University].

73.

Owens

R. E.

(2016). Language development: An introduction (9th ed.). Pearson Education Limited.

74.

Page

Wilhelm

M. S.

Gamble

W. C.

Card

N. A.

(2010). A comparison of maternal sensitivity and verbal stimulation as unique predictors of infant social-emotional and cognitive development. Infant Behavior & Development, 33(1), 101–110. https://doi.org/10.1016/j.infbeh.2009.12.001

75.

Page

M. J.

McKenzie

J. E.

Bossuyt

P. M.

Boutron

Hoffmann

T. C.

Mulrow

C. D.

Shamseer

Tetzlaff

J. M.

Akl

E. A.

Brennan

S. E.

Chou

Glanville

Grimshaw

J. M.

Hróbjartsson

Lalu

M. M.

Loder

E. W.

Mayo-Wilson

McDonald

. . . Moher

(2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ, 372, Article n71. https://doi.org/10.1136/bmj.n71

76.

Parish-Morris

Liberman

M. Y.

Cieri

Herrington

J. D.

Yerys

B. E.

Bateman

Donaher

Ferguson

Pandey

Schultz

R. T.

(2017). Linguistic camouflage in girls with autism spectrum disorder. Molecular Autism, 8, Article 48. https://doi.org/10.1186/s13229-017-0164-6

77.

Petersen

(2018). Gender difference in verbal performance: A meta-analysis of United States state performance assessments. Educational Psychology Review, 30, 1269–1281. https://doi.org/10.1007/s10648-018-9450-x

78.

Pomerleau

Bolduc

Malcuit

Cossette

(1990). Pink or blue: Environmental gender stereotypes in the first two years of life. Sex Roles, 22(5), 359–367. https://doi.org/10.1007/BF00288339

79.

Rubin

J. Z.

Provenzano

F. J.

Luria

(1974). The eye of the beholder: Parents’ views on sex of newborns. American Journal of Orthopsychiatry, 44(4), 512–519. https://doi.org/10.1111/j.1939-0025.1974.tb00905.x

80.

Rutter

Le Couteur

Lord

(2003). ADI-R: Autism Diagnostic Interview Revised. Western Psychological Services.

81.

*Salomone

Charman

Mcconachie

Warreyn

(2016). Child’s verbal ability and gender are associated with age at diagnosis in a sample of young children with ASD in Europe. Child: Care, Health and Development, 42(1), 141–145. https://doi.org/10.1111/cch.12261

82.

Sedivy

(2014). Language in mind: An introduction to psycholinguistics. Sinauer Associates.

83.

Simonsen

H. G.

Kristoffersen

K. E.

Bleses

Wehberg

Jørgensen

R. N.

(2013). The Norwegian communicative development inventories: Reliability, main developmental trends and gender differences. First Language, 34(1), 3–23. https://doi.org/10.1177/0142723713510997

84.

*Song

Cola

Plate

Petrulla

Yankowitz

Pandey

Schultz

R. T.

Parish-Morris

(2021). Natural language markers of social phenotype in girls with autism. Journal of Child Psychology and Psychiatry and Allied Disciplines, 62, 949–960. https://doi.org/10.1111/jcpp.13348

85.

Stoller

R. J.

(1984). Sex and gender: The development of masculinity and femininity. Karnac Books.

86.

Strang

J. F.

Anthony

L. G.

Song

Lai

M.-C.

Knauss

Sadikova

Graham

Zaks

Wimms

Willing

Call

Mancilla

Shakin

Vilain

Kim

D.-Y.

Maisashvili

Khawaja

Kenworthy

(2021). In addition to stigma: Cognitive and autism-related predictors of mental health in transgender adolescents. Journal of Clinical Child & Adolescent Psychology. Advance online publication. https://doi.org/10.1080/15374416.2021.1916940

87.

Strang

J. F.

van der Miesen

A. I. R.

Caplan

Hughes

daVanport

Lai

M. C.

(2020). Both sex- and gender-related factors should be considered in autism research and clinical practice. Autism, 24(3), 539–543. https://doi.org/10.1080/15374416.2020.1731817

88.

*Sturrock

Marsden

Adams

Freed

(2020). Observational and reported measures of language and pragmatics in young people with autism: A comparison of respondent data and gender profiles. Journal of Autism and Developmental Disorders, 50(3), 812–830. https://doi.org/10.1007/s10803-019-04288-3

89.

*Sturrock

Yau

Freed

Adams

(2020). Speaking the same language? A preliminary investigation, comparing the language and communication skills of females and males with high-functioning autism. Journal of Autism and Developmental Disorders, 50(5), 1639–1656. https://doi.org/10.1007/s10803-019-03920-6

90.

Tricco

A. C.

Lillie

Zarin

Colquhoun

Levac

Moher

Peters

M. D. J.

Horsley

Weeks

Hempel

Akl

E. A.

Chang

McGowan

Stewart

Hartling

Aldcroft

Wilson

M. G.

Garritty

Lewin

. . . Straus

S. E.

(2018). PRISMA extension for scoping reviews (PRISMA-ScR): Checklist and explanation. Annals of Internal Medicine, 169, 467–473. https://doi.org/10.7326/M18-0850

91.

Walsh

R. J.

Krabbendam

Dewinter

Begeer

(2018). Brief report: Gender identity differences in autistic adults: Associations with perceptual and socio-cognitive profiles. Journal of Autism and Developmental Disorders, 48(12), 4070–4078. https://doi.org/10.1007/s10803-018-3702-y

92.

Warrier

Greenberg

D. M.

Weir

Buckingham

Smith

Lai

M.-C.

Allison

Baron-Cohen

(2020). Elevated rates of autism, other neurodevelopmental and psychiatric diagnoses, and autistic traits in transgender and gender-diverse individuals. Nature Communications, 11(1), Article 3959. https://doi.org/10.1038/s41467-020-17794-1

93.

Watts

(2019, May 29). Beyond “female autism.” Playing a/part: Autistic girls, identities and creativity. https://playingapartautisticgirls.org/2019/05/29/beyond-female-autism/

94.

West

Zimmerman

D. H.

(1987). Doing gender. Gender and Society, 1(2), 125–151.

95.

Wing

(1981). Sex ratios in early childhood autism and related conditions. Psychiatry Research, 5(2), 129–137. https://doi.org/10.1016/0165-1781(81)90043-3

96.

World Health Organization. (2019). Gender, equity, and human rights. https://www.who.int/gender-equity-rights/understanding/gender-definition/en/

97.

Young

Oreve

M. J.

Speranza

(2018). Clinical characteristics and problems diagnosing autism spectrum disorder in girls. Archives de Pédiatrie, 25, 399–403. https://doi.org/10.1016/j.arcped.2018.06.008

98.

Zambrana

I. M.

Ystrom

Pons

(2012). Impact of gender, maternal education, and birth order on the development of language comprehension: A longitudinal study from 18 to 36 months of age. Journal of Developmental and Behavioral Pediatrics, 33, 146–155. https://doi.org/10.1097/DBP.0b013e31823d4f83

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.00 MB

0.08 MB