Second, this collection of cognitive programs evolved in the Pleistocene to solve the adaptive problems regularly faced by our hunter-gatherer ancestors-...

Despite a staggering body of research demonstrating sex differences in expressed emotion, very few theoretical models (evolutionary or non-evolutionary) offer a critical examination of the adaptive nature of such differences. From the perspective of a socio-relational framework, emotive behaviors evolved to promote the attraction and aversion of different types of relationships by advertising the two most parsimonious properties ofreciprocity potential, or perceived attractiveness as a prospective social partner. These are the individual's (a)perceived capacityor ability to provide expedient resources, or to (...) inflict immediate harm onto others, and their (b)perceived trustworthinessor probability of actually reciprocating altruism (Vigil 2007). Depending on the unique social demands and relational constraints that each sex evolved, individuals should be sensitive to advertise “capacity” and “trustworthiness” cues through selective displays of dominant versus submissive and masculine versus feminine emotive behaviors, respectively. In this article, I introduce the basic theoretical assumptions and hypotheses of the framework, and show how the models provide a solid scaffold with which to begin to interpret common sex differences in the emotional development literature. I conclude by describing how the framework can be used to predict condition-based and situation-based variation in affect and other forms of expressive behaviors. (shrink)

A meta-analysis was conducted to compare perceptions of Duchenne smiles, smiles that include activation of the cheek raiser muscle that creates crow's feet around the eyes, with perceptions of non-Duchenne smiles, smiles without cheek raiser activation. In addition to testing the overall effect, moderator analyses were conducted to test how methodological, stimulus-specific and perceiver-specific differences between studies predicted the overall effect size. The meta-analysis found that, overall, Duchenne smiles and people producing Duchenne smiles are rated more positively (i.e., authentic, genuine, (...) real, attractive, trustworthy) than non-Duchenne smiles and people producing non-Duchenne smiles. The difference between Duchenne and non-Duchenne smiles was greater when the stimuli were videos rather than photographs, when smiles were elicited naturally rather than through posing paradigms and when Duchenne and non-Duchenne smiles were not matched for intensity of the lip corner puller in addition to other perceiver and methodological moderators. (shrink)