Vigil's interpretation is a major step in summarizing recent knowledge about emotional behavior guided by Darwin's concept of the variation of expression of emotion. We would like to add that human behavior in general necessarily has its roots in the earliest caregiver–child interaction. In humans, any kind of behavior occurs in a context of extra-uterine social prematurity; that is to say, in a psychophysical state when terms such as “capacity” or “dominance” cannot easily be applied.
To understand human emotional development, we must go beyond the concepts of “fitness,” “cost-benefit,” and so on, because human babies are “unfit” and depend so much on the caregiving function. Hamlin et al. (Reference Hamlin, Wynn and Bloom2007) conducted an amazing social-task experiment with 6- to 10-month-old healthy infants and found that “The capacity to evaluate other people is essential for navigating the social world” (p. 557). A baby's crying, for example, may not necessarily be a gesture of submission, but instead can be an act of dominance, inducing the appearance of a caregiver (and, of course, then constitutes a fitness advantage). If this fails to happen too often, helplessness and depression follow, and crying loses its meaning as a specific social signal and only expresses despair in lieu of other outlets.
Vigil's capacity and trustworthiness components represent “within” cues, whereas interaction competencies as “between” cues might be additionally meaningful in a broader sense of early mental development. Attachment theory (Ainsworth & Bowlby Reference Ainsworth and Bowlby1991), as a key feature in understanding human socio-emotional development in early infancy, could be an expansion of Vigil's theoretical framework. Bowlby's main construct is the infant's dependence on the presence of a sensitive caregiver responsible for providing a “secure base” in an asymmetrical relationship. Thus arise the “inner working models” in the infant that are supposed to influence developing personality traits. Continuing the concept of “emotional availability,” Emde (Reference Emde and Taylor1980) points out the dyadic and dynamic aspects of emotional development in the first year of life.
As an ethological model, attachment behavior shares the central topic of the socio-relational framework of expressive behaviors (SRFB) – that is, with either proximity-seeking (affiliative) behavior or withdrawn (avoidance) behavior – but in a reflexive and intuitive manner. Patterns of infants' behavior such as displays of vulnerability (e.g., bowed head, gaze aversion, slow movement patterns, crying, and worrying behavior) are usually reactions to over-stimulation and tiredness, indicating the need for a break; whereas ongoing avoidance may emerge after experiences of neglect or maltreatment.
Corresponding to Vigil's social sphere model, empirical findings based on the emotional availability concept show the great predictive power of alternatively auto-regulative or interpersonal affect-regulation styles in mother–child interaction when the child is at the age of 4 months (Kogan & Carter Reference Kogan and Carter1996). In this light, Vigil's model for correlating individuals' social spheres and phenotypic expression could be augmented by such a “mothering” link. Beside a large body of pediatric literature, this can be supported by our own data concerning breast-feeding and bonding (Böge et al., in preparation). In comparing a clinical sample with a non-clinical one, we have found that breast-feeding is associated with a reduced incidence of developmental problems and psychopathology in children later in life – irrespective of socioeconomic status, prematurity, and other risk factors. Oxytocin-inducing “good mothering” behavior and affiliative and/or trustworthy behavior, such as more intense eye contact and proximity among females than among males, might thus also be specific to females on account of heightened receptor sensitivity, ensuring the healthy upbringing of the species.
But phenotypic behavior does not automatically represent internal states. For example, misunderstanding, apparent sensitive behavior, as well as any other double-bind communication, cannot be explained by the mechanisms of SRFB as a monadic model. The findings of changes in temporal lobe and amygdala, as well as increasing oxytocin and vasopressin levels in conflicting communication, might be indicative of an early “flight-or-fight” decision. Either on the basis of intuitive attachment, or dominance versus submissive behavior, those findings have been largely confirmed – also by our own data of elevated levels of cortisol in 4-month-old infants of mothers with postpartum depression (Bartling et al. Reference Bartling, Klapp, Dudenhausen, Lehmkuhl, Lenz and Wiefel2006). Thus, it would be worth widening the focus on conflicting states and clinical disorders, to disorders other than only stress-induced ones. As the expression of emotion relies heavily on mother–child contact and the child's potential for developing a theory of mind, autistic spectrum disorders, as well as depressive disorders, are the most interesting ones for investigation. Video interaction analyses in a clinical sample showed specific patterns in correlation with diagnostic clusters, not gender (Wiefel et al. Reference Wiefel, Wollenweber, Oepen, Lenz, Lehmkuhl and Biringen2005).
We especially like Vigil's notion, towards the end of the target article, that certain behaviors which were previously thought to be maladaptive (signs of weakness or submissiveness), might in fact be functional in humans. However, alternatively, those involuntary defeat strategies could be understood as a compromise between genetic drift and the result of attachment experiences from the first year of life, and, therefore, could be proof of a cost-benefit advantage; for example, the concept of learned helplessness in common depression. We even dare to pose the hypothesis that most of the gender differences found in childhood between girls and boys (more intense expression of emotion, more submissiveness, more group adherence) might be protective factors for children's mental health that wear off in later life, as girls are epidemiologically less prone to behavioral symptoms at a young age than are boys. From our clinical viewpoint, beneath the well-known gender differences in the incidence of several disorders we actually observed an even more rapid shift of this phenomenon over the early age span in infant psychiatry (Wiefel et al. Reference Wiefel, Lenz, Fuehrer, Kuntze and Lehmkuhl2009). Certainly we found diminished gender effects in our clinical sample when psycho-social circumstances (but not the caregiver's sensitivity as a central cue in the field) were integrated (Witte Reference Witte and Wiefel2006).
