Parapatric Speciation in the Evolution of Early Intervention for Infants and Toddlers With Disabilities and Their Families

A Brief History of Early Intervention

The origins of early intervention date back to the late 1800s (Dunst, 1996). The term early intervention, as now commonly used, has throughout its history been described as infant stimulation (Bronfenbrenner, 1975), early stimulation (Cunningham, 1979), infant intervention (Bromwich, 1976), and infant education (Painter, 1968). Early intervention as described in this brief history encompasses these as well as other terms (e.g., Gibson, 1984) for describing practices for promoting the learning and development of infants and toddlers with disabilities and young children at risk for developmental delays.

Contemporary interest in the value and benefits of early intervention can be traced to a number of influential events during the 20th century. Theory and research were used to build a case for the plasticity of infant and toddler learning and development, and the kinds of experiences that can affect or alter the behavior of very young children (e.g., Bronfenbrenner, 1975; Caldwell, 1970). In a series of studies conducted between 1938 and 1950, different kinds of environmental interventions were found to be related to both the immediate and long-term developmental outcomes of young children with and without disabilities (e.g., Kirk, 1950; Skeels, Updegraff, Wellman, & Williams, 1938; Spitz, 1945). These studies included comparisons where the experiences provided to intervention group participants all had discernable positive effects on the children compared with the control or comparison group participants. These studies, which are rarely cited today, proved an early tipping point for building the case that early intervention could have positive effects on young children’s learning and development.

Theoretical formation by Hebb (1949), Hunt (1961), and Bloom (1964) was instrumental in building the case that experiences early in a child’s life could have either positive or negative effects on learning and development. Both developmental (e.g., Piaget, 1952) and operant (Bijou & Baer, 1961) theories played central roles in the identification of the particular kinds of experiences that influence infant and toddler behavior. Hunt (1961), for example, built a convincing case that planned and naturally occurring experiences matter a great deal in affecting child learning and development. In a series of subsequent studies, Hunt (1987) demonstrated that the contrasting experiences and opportunities afforded to infants and toddlers had differential consequences on the children’s behavior and development.

Early intervention programs for young children with, or at risk for, developmental delays or disabilities expanded rapidly in the 1960s, 1970s, and 1980s (e.g., Bricker, 1982; Tjossem, 1976). These included both home-based and center-based programs where the practices used by practitioners in those programs were based on theory and research (see, for example, Affleck, McGrade, McQueeney, & Allen, 1982; Weikart & Lambie, 1970). Many of these programs, and especially home-based programs, involved the children’s mothers as the primary source of children’s learning experiences and opportunities (Bricker & Casuso, 1979; Bromwich, 1976). These home-based programs often used parent–infant interaction theory and research (Brody, 1956) for developing and implementing procedures for promoting mothers’ adoption and use of interactional behavior that supported and strengthened child learning and development.

Early intervention up until 1986 mirrored advances in theory and research in early education, child development, and parent education (e.g., Hunt, 1979; Lally & Honig, 1975). At the time a bill to amend the Education of the Handicapped Act “to authorize an early intervention program . . . for handicapped infants” (U.S. Congress House of Representatives Committee on Education and Labor, 1986, p. 1) was introduced, early intervention, as we then knew it, was about to undergo sudden parapatric speciation, where the division into two different types of early intervention generally went unnoticed or at least unacknowledged.

Contrasting Definitions of Early Intervention

The sudden change that occurred in the field of early intervention at the time of the passage of the Part H legislation produced an evolutionary split in how early intervention was defined. This in turn has had major implications for how early intervention was conceptualized and practiced. Prior to the Part H legislation, a primary focus of early intervention was the learning opportunities afforded to infants and toddlers that used to influence changes in the children’s behavior and development. In contrast, the definition in the 1986 Part H legislation, and subsequent reauthorizations of the Act, defined early intervention in terms of the services provided by qualified professionals to infants and toddlers and their families.

Pre Part H Definitions

Table 1 shows a chronology of definitions of early intervention that appeared in the literature between 1967 and 1986. The definitions include a number of key terms that reflect what were then considered important features of early intervention. The terms experiences or activities appear in most of the definitions and refer to the fact that the learning opportunities afforded to infants and toddlers were interventions. The terms facilitate, achieve, and reach indicate that the learning opportunities were expected to produce targeted behavior change. The terms intentionally organized, carefully planned, and of a planned nature indicate that the experiences used as early intervention were carefully selected and implemented to influence changes in child learning and development. The definitions, taken together, emphasize the fact that early intervention was about the kinds of activities that were intentionally used with young children to produce desired outcomes and consequences.

OPEN IN VIEWER

Table 1.

A Chronology of Definitions of Early Intervention 1967–1986

Year	Definition
1967	A planned sequence of events, activities and experiences occurring in a prescribed time period intentionally organized and implemented to achieve a desired result. (Barsch, 1967, p. 546)
1975	Provide opportunities for the infant to actively engage his [or her] environment and by extending infant-initiated activities . . . . to facilitate child development. (Lambie, Bond, & Weikart, 1975, p. 278)
1979	[Early intervention] is concerned with providing meaningful and appropriate educational experiences to preschool children [by] structuring the learning environments of the children. (Garwood, 1979)
1981	Programs of enrichment designed to provide developmentally appropriate activities to babies and toddlers who have or who are at-risk for a variety of conditions. (Denhoff, 1981, p. 32)
1981	Carefully planned and designed activities, events, and experiences organized and implemented to reach specified objectives and goals. (Dunst, 1981, p. 9)
1984	Early intervention refers to therapeutic (excluding drug or surgical manipulation) or educational intervention . . . of a planned nature aimed at eliminating a current or anticipated deficiency in a target population. (Bricker, Bailey, & Bruder, 1984, p. 374)

One of the consequences of the experience-based definitions of early intervention was a flurry of activity designed to identify the kinds of experiences that were most likely to have development-enhancing characteristics and consequences. These efforts were guided primarily by developmental (Fowler, 1962) and operant learning (Horowitz, 1968) theories, knowledge of the social (parental) determinants of infant and toddler development (Bromwich, 1981), and the early tenets of ecological theories of child, parent, and family development (Bronfenbrenner, 1977). The results were the development of early intervention curricula (e.g., Furuno et al., 1979), operant and response-contingent learning interventions (e.g., Lancioni, 1980), parent training methods and procedures (e.g., Sandler, Coren, & Thurman, 1983), parent–infant interaction practices (e.g., McCollum, 1984), and the use of different kinds of instructional practices to influence infant and toddler learning and development (e.g., Hart & Risley, 1978). Notwithstanding the fact that some of those efforts proved not to be optimally effective (e.g., Halpern, 1984), a common denominator was the search for the kind of experiences that could be used as early intervention to affect changes in child learning and development.

Part H/Part C Definitions

The passage of the Part H early intervention legislation marked a dramatic shift in the history of early intervention for young children with disabilities. The shift was especially pronounced in terms of the change in the definition and descriptions of early intervention. Table 2 shows how early intervention was/is defined in the Congressional Report and the four pieces of legislation that include the Part H and now the Part C Infants and Toddlers With Disabilities program. The House Report and different pieces of legislation all describe early intervention in terms of professional services designed to meet the developmental needs of infants and toddlers where the services are provided by qualified personnel.

OPEN IN VIEWER

Table 2.

Part H and Part C Definitions of Early Intervention

Year	Definition
1986	Early intervention services mean developmental services [that] include family training, counseling, and home visits; special instruction; speech pathology and audiology; occupational services; physical therapy; and [other professional services] (U.S. Congress House of Representatives Committee on Education and Labor, 1986)
1986	Family training and counseling; child special instruction and therapy; case management and other [professional] services to meet a child’s developmental needs (Education of the Handicapped Act Amendments of 1986, Pub. L. No. 99–457, 100 Stat. 1145, 1986)
1990	Educational and therapeutic services to the child, and counseling support and other services to parents, provided by regular contact with professionals (Individuals With Disabilities Education Act of 1990, Pub. L. No. 101–476, 104 Stat. 1142, 1990)
1997	Child and family services to meet a child’s developmental needs provided in natural environments (Individuals With Disabilities Education Act Amendments of 1997, Pub L. No. 105-17, 111 Stat. 37, 1997)
2004	Services that are designed to meet the developmental needs of infants and toddlers with a disability (Individuals With Disabilities Education Improvement Act of 2004, Pub. L. No. 108–446, 118 Stat. 2647, 2004)

The consequence of a shift to a service-based definition of early intervention was the kind of stepped division that is characteristic of parapatric speciation. This is easily illustrated by a content analysis of the Part C Infants and Toddlers With Disabilities sections of the Individuals With Disabilities Education Improvement Act (2004). Electronic searches for terms that were the key features of early intervention prior to Part H (see Table 1) found that the word learning appeared only once and as part of the requirements for a public awareness program (Sec. 635(a)(6)). The terms experience or opportunity appear 5 times, only 1 of which refers to activities used to promote infant and toddler learning or development (Sec. 639(a)(4)). The terms facilitate or enhance appear 7 times, only 2 of which refer to the processes used to promote infant and toddler development (Sec. 631(a)(1), Sec. 631(a)(4)). The terms development or developmental appear 38 times, only 4 of which refer to the enhancement of child development (Sec. 631(a)(1), Sec. 632 (c), Sec. 635(a)(3), Sec. 636(a)(2), Sec. 636(d)(3)). (The terms are most often used to describe developmental delay, different developmental domains, or personnel development.) Now consider the terms service and services. They appear 179 times in the Part C sections of the legislation. They most often describe discipline-specific services, the individualized family service plan (IFSP), and service coordination. Some simple calculations of the percentage of times different terms are used in the Part C legislation show that only 3% of the time the terms refer to experience-based early intervention, whereas 91% of the time the terms refer to service-based early intervention. Parenthetically, the same analyses performed on the recently released Part C Final Regulations (34 CFR Part 303) found that the term service or services appear 2,412 times, whereas child learning (experience or opportunity) appears only 3 times!

The influence of a service-based definition of early intervention was almost immediately felt in terms of State implementation of the Part H legislation and the ways in which states now define and describe early intervention. A content analysis of the descriptions of early intervention on each State and the District of Columbia websites finds that most (N = 43) indicate that their mission or goal is to provide supports and services, systems of supports and services, or statewide systems of supports and services delivered by qualified professionals. Eight states describe early intervention in terms of both services and some type of experience-based early intervention (mostly child involvement in daily routines and activities). Only one of these states describes early intervention in terms of children’s learning in the context of relationships with their families and other caregivers in everyday routines, activities, and community settings in addition to service-based practices. The overall pattern of results clearly shows that the Part H/Part C Infants and Toddlers With Disabilities legislation successfully populated state’s early intervention practices with a service-based gene pool.

Consequences of Parapatric Speciation

Close inspection of the different versions of the Part H/Part C early intervention legislation, and states’ interpretation and implementation of the requirements of the legislation, shows very little substantive change in its 25-year history. What changes have occurred have been mostly tweaking or wordsmithing (e.g., changing the term case management to service coordination). Placed in the context of the current knowledge base, the Part C program has not kept pace with advances in theory, research, and practice (e.g., Feldman, 2004; Guralnick, 2005; McWilliam, 2010; Odom & Wolery, 2003; Shonkoff & Meisels, 2000). Evidence from a number of sources indicate that how Part C early intervention is generally practiced does not match what is considered either recommended or evidence-based early intervention practices (McLean, Snyder, Smith, & Sandall, 2002; Odom, McLean, Johnson, & LaMontagne, 1995) and that there is often a disconnect between what Part C practitioners say or believe they do and what actually occurs in the name of early intervention (McBride & Peterson, 1997; Roggman, Boyce, Cook, & Jump, 2001). There are niches and habitats scattered throughout the United States where contemporary early intervention is practiced in Part C programs (see especially Guralnick, 2005), but there is very little evidence that these practices have been taken to scale in Part C programs, that these practices have been widely adopted by Part C programs or practitioners, or that Part C practices have been broadly influenced by contemporary theory and research.

One reason for the failure of Part C to evolve has been the fact that the definition of early intervention has remained stagnant for 25 years where that definition is inconsistent with contemporary evidence about the kinds of experiences and opportunities, and conditions under which infant and toddler learning and development are likely to be optimized (Shonkoff & Phillips, 2000). Moreover, the continued emphasis on professional services as the unit for defining early intervention has taken, in the past and continues to take, Part C intervention on an evolutionary path that ever widens the divide between research evidence and Part C practices.

The consequences of the parapatric speciation of Part H/ Part C early intervention has been manifested in a number of ways. First and foremost, there was a shift in emphasis toward professional services together with a concomitant decrease in attention to the key characteristics of child learning experiences and opportunities. This led to a lack of specificity in terms of exactly what it was that “made up” a service and how it was expected to produce desired outcomes. A related consequence was professionals providing services directly to children without meaningfully involving the family in the interventions. Some simple calculations show that twice-a-week hourly intervention or therapy, in the absence of parent involvement, accounts for only about 2% of the total waking hours of a 1-year-old child (Roffwarg, Muzio, & Dement, 1966), hardly enough time for any kind of intervention to make a meaningful difference in a child’s life (see Mahoney & MacDonald, 2007; McWilliam, 2000).

A third consequence manifested itself in terms of how IFSPs are written and implemented. For the most part, the focus of IFSPs has been on child (and sometimes family) outcomes and simply the listing of services, which supposedly will result in those outcomes. A fourth consequence was the decontextualization of early intervention where services for the most part are not implemented in settings or contexts necessary for functional skill acquisition. Advances in early intervention theory and research prior to and at the time of the Part H legislation made clear that the contexts of early intervention were extremely important if optimal benefits were to be realized (e.g., Ballard, 1986; Cohen, Hulls, & Rhine, 1978). A fifth consequence was a lack of concern for the particular instructional practices used to promote infant and toddler learning or how family capacity to engage in interactions to support child learning was promoted and strengthened. As part of a study investigating the kinds of instructional practices that Part C practitioners either suggested or taught parents to use with their children, the majority of parents indicated that they were told to simply repeat the same activity over and over until their children demonstrated the expected behavior, hardly an effective instructional practice (Dunst, Bruder, Trivette, Raab, & McLean, 1998).

Finally, a sixth consequence is the fact that Part C early intervention has become a professionally driven enterprise, especially in states with private provider models where there is a vested financial interest in prescribing and providing professional services (see especially Hewlett & West, 1998). The latter is especially true in states that depend on Medicaid funding to support the provision of professional services particularly where those services are reimbursable only if provided to infants and toddlers by Part C practitioners. It was only a matter of time that Part C early intervention has begun to be described as an early intervention industry (e.g., http://antillia.us/whythisworkshop.php; www.birth2five.org).

Conclusion

The shift from an experience-based to service-based approach to early intervention that resulted from Part H legislation was somewhat unintentional but certainly unfortunate. (I say somewhat unintentional because just prior to the passage of the Part H legislation, voices from different professional organizations were very loud in terms of the disciplines they wanted explicitly listed in the Act.) The consequences to a large degree were the result of the way in which early intervention was defined and how a service-based approach has taken early intervention far afield from what at the time and what we now know are important features and characteristics of effective early intervention practices. There is an urgent need for Part C to enter a new niche and habitat that is more consistent with current theory, research, knowledge, and practice (Dunst, 2007, 2011). Accordingly, the legislation and the rules governing the Act need to be changed, starting with an updated definition of early intervention, and preferably an operational definition that is based on contemporary theory, research, knowledge, and practice.

An operational definition of early intervention would include the essential characteristics of practices (experiences, opportunities, activities, etc.) and how and why they are expected to have specified outcomes based on empirical evidence. The definition would also specify the agents of the provision of those experiences and opportunities. This would provide an opportunity to reemphasize the fact that the original intent of Part H/Part C was to build and strengthen family capacity to provide early intervention to their children with support and guidance from practitioners (Barber, Turnbull, Behr, & Kerns, 1988). The definition could go one step further by stating the kinds of evidence-based instructional practices that a family could use to promote child learning and development as part of the learning opportunities afforded to a child (Bailey & Wolery, 1992).

An operational definition of early intervention would inform all the corollaries of the definition that are logical extensions. An operational definition that includes the essential elements and features described above would have direct implications for how assessment practices, IFSPs, natural environment, and other Part C early intervention practices are defined, operationalized, and implemented. For example, natural environment practices would be described as those everyday activities and routines that provide infants and toddlers experiences and opportunities of known qualities intended to increase child participation in real-life learning to promote and enhance child development where the family supports and encourages child participation and competence in the activities (Kahn, Stemler, & Berchin-Weiss, 2009; Vincent & McLean, 1996). Any Part C practice could easily be couched in this kind of description.

Any changes in the Part C definition of early intervention, and subsequently all its corollaries, ought to be informed by available research evidence. The call for adoption of scientifically based practices appears 28 times in the P. L. 108–446 legislation (2004) but unfortunately only once in the Part C sections of the Act (Sec. 635(a)(2)). Nonetheless, the one statement pertaining to scientifically based research could be paraphrased and stated as,

State policy that is in effect should ensure that early intervention practices be based on scientifically-based research to ensure that the best learning experiences and opportunities possible are made available and provided to infants and toddlers with disabilities by their families.

In what I consider a seminal paper preventing parent involvement in early childhood intervention for young children with disabilities from evolving along a path based on faulty logic, Foster, Berger, and McLean (1981) stated that

Good ideas should be commended and if they work they should be adopted. Even exceptional ideas, however, should be reviewed periodically to see whether the premises under which they were adopted still hold true and their influence is still positive. (p. 55, italics added)

Part H was a good idea. However, the time to examine and revise the Part C legislation in light of current theory, knowledge, research, and practice is long past due. The interested reader is referred to Dunst (2007, 2011) for critical examinations of Part C early intervention and what evidence-based practices might look like as part of changes in the Part C legislation.

I close with one last analogy between human evolution and early intervention. Homo genus is the common ancestor of both modern humans (Homo sapiens) and the Neanderthals (Tattersall, 1999). The reason Homo sapiens survived and the Neanderthals did not was the fact that Homo sapiens showed more rapid evolution and adaptations to the challenges and changes they faced, whereas the Neanderthals showed arrested evolution and a failure to adapt to the very same kind of challenges and changes (Mellars, 1998). The continued failure of Part C to change and adapt based on new knowledge and research evidence might result in the same grisly fate that the Neanderthals experienced (Tattersall, 1999).