Abstract
In The Face of Emotions, which was Carroll Izard’s first major attempt at elaborating his differential emotions theory (DET), he stated that the book “presents a theoretical framework for the study of emotions and their role in personality and interpersonal processes.” Yet, over the years, his contribution to personality theory has generally been overshadowed by the attention focused on his views on facial expressions and the structure of emotions. This article will begin with a brief overview of the DET perspective on personality development. Then, it will examine how the DET framework can be used to organize recent findings from three lines of research on adult personality. It will conclude with suggestions for future research as well as some personal recollections.
I was one of Carroll Izard’s graduate students at the University of Delaware during the early 1990s, and over the years I have had the opportunity to work with him on a number of articles and book chapters from the differential emotions theory (DET; Izard, 1971, 1977, 1991) perspective. Each of the pieces focused on a different topic, and every time I completed one of them, I had a renewed appreciation for the comprehensiveness and versatility of his theory. As a result of my immersion in the DET perspective, I have a tendency to see things through that lens even after my research interests have shifted from developmental to adult personality psychology. In this article, my goal is to make the case that even though DET has been elaborated primarily in the context of developmental research in recent years, it does a remarkably good job of accommodating some exciting new findings from diverse lines of research on adult personality and can serve as a comprehensive framework for organizing research on personality development across the life span. Given that the aspects of DET that have probably received the most attention are its position on the discreteness of emotions and the ontogeny of facial expressions, the focus of this article may come as a surprise to some readers of Emotion Review. However, as Dante Cicchetti mentions in his overview to this special section, Carroll’s early research focused primarily on adult personality (Cicchetti, 2015), and a perusal of his theoretical writings reveals his wide-ranging background and interest in personality psychology throughout his career (e.g., Izard, 1979, 2009). In the Preface to The Face of Emotions, which was Carroll’s first major attempt at elaborating DET, he states that the book “presents a theoretical framework for the study of emotions and their role in personality and interpersonal processes” (Izard, 1971, p. v). Quite remarkably, in this book, he already presented the backbone of his theory of personality. Over the years, as Carroll incorporated findings from diverse lines of research, his perspective on personality development evolved and became more comprehensive, articulated, and multileveled. However, he has not presented an integrative summary of his current views on personality development in a single publication; thus, one of the contributions of this article will be to provide a synthesis of his insights on personality development from his writings on various topics.
This article will begin with a brief overview of the DET perspective on personality development and present some empirical evidence in support of some of its core propositions. Then, it will examine how the DET framework can be used to organize recent findings from three lines of research on adult personality. It will conclude with suggestions for future research as well as some personal recollections.
Emotions as Precursors of Temperament and Personality Traits
Following Silvan Tompkins (1962, 1963), DET states that emotions serve as the primary motivational and organizational systems for humans across the life span (Izard, 1971, 1977, 1991). Compared to the young of other species, human infants are born relatively helpless, but they come endowed with precocious emotion systems, which enable them to signal their needs, desires, and distress to their caregivers through affective channels. Each emotion is preadapted over the course of evolution and tends to organize thoughts and actions in a particular manner. Given that infants widely vary in their thresholds for experiencing each of the emotions as well as in their environmental circumstances, they differ in their propensities to experience particular emotions. These individual differences in emotional experiences as well as capacities to regulate emotions become consolidated into temperament traits. Over time, as repetitive emotion experiences become increasingly linked to cognitive patterns, they form stable emotion schemas which, in turn, become elaborated into personality traits (Izard, Libero, Putnam, & Haynes, 1993).
Some of the foregoing propositions were examined in a three part longitudinal project. In the first study, infants’ full-face and component expressions of joy, interest, sadness, and anger were coded using AFFEX (Izard, Dougherty, & Hembree, 1983) at 13 and 18 months, and developmental changes in the form of emotion expressions as well as the relations between the emotion expressions with maternal ratings of their infants’ temperament at 18 months were examined (Izard & Abe, 2004). According to DET, full-face expressions index intense or high arousal emotions, whereas component expressions index milder or regulated emotions (Abe, Beetham, & Izard, 2002; Izard, 1971, 1977). Given that infants show rapid advances in their ability to regulate their emotions during the second year of life, we hypothesized that there would be a decrease in full-face expressions and an increase in component expressions. These predictions were supported. Moreover, consistent with the view that full-face and component expressions index different intensities of emotion, full-face negative expressions, but not component negative expressions, were associated with maternal ratings of difficult temperament; and component positive expressions, but not full-face positive expressions, were negatively correlated with difficult temperament.
In the second longitudinal study, we examined whether infants’ emotion expressions at 18 months predicted maternal ratings of their children’s Big Five personality traits at 3.5 years old (Abe & Izard, 1999a). The patterns of findings were strikingly similar to those obtained with adults using self-report measures: neuroticism was associated with negative emotion expressions; extraversion was associated with intense positive emotion expressions; conscientiousness and agreeableness were associated with milder or regulated positive emotion expressions; openness to experience was positively correlated with intense positive emotion expressions, and negatively correlated with intense negative emotion expressions. The findings from this study also mapped on nicely with Rothbart’s (2007) three dimensional model of temperament. According to her model, the first broad dimension, effortful control (which assesses characteristics similar to conscientiousness and agreeableness) is associated with low-intensity pleasure; the second dimension, extraversion/surgency, is associated with high-intensity pleasure; the third dimension, negative affectivity is associated primarily with discrete negative emotions.
In the third longitudinal study, I found that maternal ratings of children’s personality traits at 3.5 years of age showed theoretically coherent patterns of relations with children’s behaviors during a wide range of laboratory procedures at 5 years of age, as well as with their self-ratings of self-concepts and perceptions of control during adolescence (Abe, 2005). As expected, conscientiousness and agreeableness, were associated with various measures of self-regulation at both ages, and extraversion showed a mixed pattern of relations with the outcome measures. In this study, negative emotionality at 3.5 years of age was assessed using a measure of irritable distress in addition to fearful distress. Consistent with expectations, both measures of negative emotionality were associated with internalizing symptoms, but only irritable distress was negatively correlated with scholastic competence, prosocial behavior, and internal locus of control at follow-up—thus providing further support for the view that even though anger and fear share similarities, they also have distinct correlates (e.g., Izard, 1991; Rothbart, 2007).
Given that the measures of infants’ emotion expressions in the original longitudinal study were obtained prior to the emergence of full-fledged personality traits, taken together, the foregoing studies provided strong support for the DET view that emotions are precursors or the fundamental “building blocks” of personality traits and self-concepts (Abe & Izard, 1999a; Izard et al., 1993).
Towards a Multileveled View of Personality Development
According to DET, traits are nevertheless only one domain of personality. As children show rapid advances in their cognitive and language abilities from early to middle childhood and their social environment expands and becomes more demanding, the affective system becomes increasingly integrated with the cognitive and motor systems which, in turn, leads to the construction and consolidation of control mechanisms for monitoring, regulating, and utilizing emotions (Abe & Izard, 1999b; Ackerman, Abe, & Izard, 1998). These control mechanisms consist of emotion knowledge (EK), emotion regulation (ER), and emotion utilization (EU; Izard, Trentacosta, King, Morgan, & Diaz, 2007), and according to Carroll, they are also the core developmental facets of emotional intelligence (Mayer, Salovey, & Caruso, 2004). Even though the increasing intersystem communication between the emotions, cognitive, and motor systems depends on the maturation of brain structures, which continues through adolescence and even early adulthood (Izard & Ackerman, 1997), it does not unfold automatically as a function of innate biological processes; rather, it involves complex interactions and transactions among biosocial and environmental systems (Izard, 2002). According to DET, the relations between emotion traits and the control mechanisms are bidirectional, and traits may operate interactively, or as mediators or moderators in affecting personality development (Izard, 2002; Izard et al., 2007). For example, negative emotionality may overtax the child’s incipient self-regulatory abilities and interfere with the development of effective EK/ER/EU skills, but the development of effective EK/ER/EU skills may also enable a child to inhibit and perhaps even override their trait-based tendencies. Thus, early individual differences in emotion traits can become amplified or attenuated through complex transactions with the environment and set children off on widely varying developmental trajectories.
According to DET, personality development in adulthood continues to involve the complex interplay between personality traits and the control mechanisms, as well as the increasing stabilization of emotion schemas and self-concepts (Dougherty, Abe, & Izard, 1996; Izard & Ackerman, 1997). The intersystem coordination between the affective and cognitive systems, which contributes to the increasing consolidation of EK/ER/EU skills, continues to develop throughout adulthood as a function of experiences and must, in fact, be negotiated at each stage of development. A key process involved in the increasing integration between the affective and cognitive systems is the ability to symbolize complex emotion feelings in phenomenological consciousness and to translate it into language. The emotion system becomes one of several interacting subsystems of personality in adulthood, and “first-order” or basic emotions become rare, as emotions become increasingly suffused with thought. Nevertheless, the emotion and cognitive systems retain their distinct functional properties and emotions continue to serve as the primary motivational and organizational systems across the life span (Izard, 1971, 2007, 2009).
In its emphasis on how emotion traits and self-regulation reciprocally influence one another and interact in complex ways to foster personality development, DET shows striking similarities with some of the multileveled integrative theories proposed by contemporary personality psychologists (e.g., McAdams & Olson, 2010; Roberts, 2009; Shiner & Caspi, 2012).
Recent Research on Personality Development in Adulthood
The DET model of personality development can account for the apparent paradox that personality traits show both stability and change in adulthood. Contrary to the view long espoused by trait theorists that personality traits are “essentially fixed by age 30” (McCrae & Costa, 1994), data from several large-scale studies provide ample evidence that there is meaningful and significant change in mean levels of personality traits throughout adulthood, with the general trend that most people show decreases in neuroticism and increases in agreeableness and conscientiousness from early to middle and even later adulthood (e.g., Specht, Egloff, & Schmukle, 2011). These patterns of findings cannot be attributed primarily to the unfolding of intrinsic maturational processes, as there is substantial interindividual variability in the direction and rate of change as well as cohort differences (e.g., Bleidorn et al., 2013; Mroczek & Spiro, 2007). The changes in mean levels of personality traits during adulthood are more likely due to the increasing integration of the affective and cognitive systems, which contribute to normative advances in EK, ER, EU skills which, in turn, may exert a bottom-up influence on traits (Dougherty et al., 1996). A substantial body of research has, in fact, found that in general people exhibit a more sophisticated understanding of emotions as well as report higher levels of emotion regulation and improved emotion experiences between early to later adulthood (e.g., Carstensen et al., 2011; for review see Magai, 2008); thus, emotion characteristics show changes that parallel personality changes in adulthood. However, DET would also predict that most people are likely to maintain their rank order position on personality traits relative to their peers or age group (Izard et al., 1993) because personality traits tend to become more entrenched over time (Izard & Ackerman, 1997) as emotions become increasingly linked to other emotions and cognition to form stable self-concepts, and people seek out and create environments that confirm their self-concepts. The research on personality trait development, indeed, also provides robust evidence for the increasing rank order stability or consistency in personality traits in adulthood, at least until older age (e.g., Specht et al., 2011).
A substantial body of research also provides support for the DET view that emotion traits can act as both mediators and moderators in influencing development (Izard, 2002; Izard et al., 2007) and thereby may at times be associated with unexpected long-term outcomes (for a recent review see Hampson, 2012). To take one example, neuroticism has long been associated with a host of negative intrapersonal and interpersonal outcomes across the life span and has also been shown to be a predictor of mortality and disease in some studies, which is not surprising, given that the core characteristic of this personality dimension is negative emotionality. However, a growing number of studies also suggest that when combined with high levels of self-regulation, neuroticism may in some cases promote health-enhancing behaviors, presumably by fostering hypervigilance. For example, a recent large-scale study found that the anxiety component of neuroticism had a synergistically positive effect on health as evidenced by lower levels of inflammation, BMI, and chronic diseases when combined with high levels of conscientiousness (Turiano, Mroczek, Moynihan, & Chapman, 2013). The phenomenon of “healthy neuroticism” not only lends support to the DET view that personality traits interact with self-regulatory abilities in predicting adaptive outcomes (Izard, 2002; Izard et al., 2007), but also may serve as a prime example of what Carroll increasingly emphasized was the optimal mode of emotion regulation, namely, emotional utilization, which refers to the ability to harness the adaptive energy associated with emotions for beneficial purposes (Izard et al., 2011).
A growing body of research using narrative approaches has also provided support for the DET view that healthy personality development in adulthood involves the increasing integration between the affective and cognitive systems (Izard, 1971) and that translating emotion experiences into language plays an important role in this process (Izard, 2009). Interestingly, these studies have typically focused on traumatic events, which according to DET are those rare occasions that adults experience “first-order” or basic emotion responses unmediated by higher order cognition (Izard, 2007). In a series of qualitative studies focusing on people who experienced difficult life transitions, King and colleagues found that individuals who showed increases in ego development or increases in complexity of thinking about self and others over time (for review see e.g., King, 2011, p. 168) consistently wrote “vivid, engaged, and emotionally rich stories” as well as demonstrated “a striking sensitivity to their own mental processes.” Thus, both the processing of emotions associated with the turning points as well as reflecting on the meaning of the emotion experiences were essential for personality growth and development. Similarly, Pennebaker’s research on expressive writing reveals that merely venting emotions about a traumatic event or merely describing it in detail was not associated with salutary outcomes. It was only when participants wrote about both their thoughts and feelings associated with an emotional upheaval and when their writing samples showed evidence of both emotion activation and high levels of cognitive processing, as assessed by a computerized text analysis program, that they showed enhanced psychological and physiological functioning at follow-up (for recent review see Pennebaker & Chung, 2011).
Concluding Remarks and Personal Recollections
In The Face of Emotions, Carroll presented the following statement in italics: “The emotions are viewed not only as the principal motivational system but even more fundamentally as the personality processes which give meaning and significance to human existence” (Izard, 1971, p. 183). As Ross Thompson reminds us in his contribution to this special section, when Carroll began elaborating on his theory of emotions, “emotion was at the margins of developmental and personality theory” (Thompson, 2014), so it is difficult to imagine just how bold and radical such a pronouncement was at the time. In the ensuing years, the view that emotions play a central role in personality development has gained wider acceptance (e.g., Block, 2002; Carstensen, Charles, Issacowitz, & Kennedy, 2003; Rothbart, 2007; Shiner & Caspi, 2012) and significant strides have been made in understanding the role of emotions in personality processes. Nevertheless, many questions still await investigation. One important avenue for extending research on emotion and personality relations from a DET perspective is to investigate how developmental changes in EK, ER, and EU might be associated with developmental changes in personality traits. As mentioned earlier, there are striking parallels in age-related trends for emotion characteristics and personality traits between early and later adulthood. Yet, these two lines of research have surprisingly been conducted independently of one another. Another important avenue for extending research on emotion and personality relations is to focus more on discrete emotions (e.g., Abe, 2004; Izard et al., 1993). Carroll always viewed the dimensional and discrete emotion approaches as complementary, but he was also dedicated to elucidating how discrete emotions added incremental value over purely dimensional approaches throughout his career (see Youngstrom, 2014).
Carroll not only theorized about personality development but also fostered it in others, so I would like to conclude this article on a more personal note. During the Festschrift held at the University of Delaware in October 2012, Carroll’s colleagues and former students gave moving tributes, describing the profound impact his work has had on various subfields of psychology as well as the profound impact his personality has had on their lives. Some of the adjectives I recall used to characterize him included: “authentic,” “optimistic,”, “tenacious,” “Southern gentleman,” and “young at heart.” Many speakers also mentioned his humility and generosity. As I was listening to the tributes, I felt everyone was trying to capture that special human quality that Carroll has, which inspires so much respect and affection in others, and was reminded of what the political philosopher, Hannah Arendt, referred to as “the human quality of greatness—or the very level, intensity, depth, and passionateness of existence,” which far transcends any tangible accomplishments. It has been almost two decades since I was at UD, but many of his causally proffered comments still resonate deeply with me. According to DET, love can be defined as shared joy and interest in a safe interpersonal environment (Izard, 1977). So I’d like to end this article by saying: Thank you, Carroll, for your warm encouragement and support the past 20 plus years, which has fostered my personality development and for all of the moments of EI and EJ, which continue to nourish my life! Love, Jo Ann.