Evolutionary psychologists need to distinguish between the evolutionary process, ancestral selection pressures, and psychological mechanisms

Age differences in facial trustworthiness perception are diminished by affective processing

While perceptions of facial trustworthiness usually serve as our first references for social interactions, these impressions may ultimately turn out to be inaccurate or unreliable. Compared with younger adults, older adults generally face a higher risk of fraudulent exploitation; the characteristics of older adults' facial trustworthiness perception may play an important role in revealing the underlying mechanism of their being cheated. Previous studies have demonstrated that, in comparison with their younger counterparts, older adults tend to overestimate strangers' facial trustworthiness. In the present study, two experiments were conducted, aiming at testing (1) the age-related differences in facial trustworthiness perceptions (Experiment 1) and (2) whether any interventions (e.g., encouraging more deliberative processing or more affective processing) could be applied to help older adults reduce their tendency to overestimate trustworthiness, thus reducing their facial trustworthiness ratings to a lower level (Experiment 2). The results indicated that (1) consistent with previous studies, older adults provided higher trustworthiness ratings for unfamiliar faces than did younger adults (Experiment 1) and (2) more importantly, affective processing instead of deliberative processing could benefit older adults in their assessments of facial trustworthiness, leading them toward demonstrating similar-not significantly higher-levels of trust toward strange faces as younger adults (Experiment 2). A possible mechanism was offered, suggesting that affective processing might help older adults to detect negative cues in unfamiliar faces.

Meeting now suggests we will meet again: implications for debates on the evolution of cooperation

Humans are often generous, even towards strangers encountered by chance and even in the absence of any explicit information suggesting they will meet again. Because game theoretic analyses typically conclude that a psychology designed for direct reciprocity should defect in such situations, many have concluded that alternative explanations for human generosity—explanations beyond direct reciprocity—are necessary. However, human cooperation evolved within a material and informational ecology: Simply adding consideration of one minimal ecological relationship to the analysis of reciprocity brings theory and observation closer together, indicating that ecology-free analyses of cooperation can be fragile. Using simulations, we show that the autocorrelation of an individual's location over time means that even a chance encounter with an individual predicts an increased probability of a future encounter with that same individual. We discuss how a psychology designed for such an ecology may be expected to often cooperate even in apparently one-shot situations.

The symbolic self in evolutionary context

We propose that the capacity for a symbolic self(a flexible and multifaceted cognitive representation of an organism's own attributes) in humans is a product of evolution. In pursuing this argument, we note that some primates possess rudimentary elements of a self (an objectified self) and that the symbolic self (a) is a trait that is widely shared among humans, (6) serves adaptive functions, and (c) could have evolved in response to environmental pressures, with ecological and social pressures being of particular relevance. We suggest that these two environmental pressures caused the symbolic self to emerge in the Pleistocene epoch as an adaptation for Homo erectus, and we review the possible functions served by such an adaptation.

Altruism and the hypothesis of meta-selection in human evolution

According to the meta-selection hypothesis, which postulates a special kind of group selection, organized and cohesive human groups became higher-level breeders. These higher-level breeders had selective power to manipulate their members by a rewards-costs system of social exchange in such a way that altruism beyond reciprocity, which otherwise would be a liability, became a potential fitness advantage for those who were able to strike a balance between altruistic attitudes resulting from meta-selection and self-interest resulting from natural selection. The relationship among non-kin members within a group became more similar to that among kin members vis-à-vis altruism beyond reciprocity; social exchange became flexible in its exchange rates, following cultural norms; and group schema developed as an instrument for the fine-tuning of social adjustment and the tightening of group control over private life. The fragment of the discussion with Barkow gives an idea how complex and arduous the testing of the meta-selection hypothesis will be. But whatever the results of testing show, it is hoped that the theme of meta-selection opens new alternatives for thinking about the old puzzles of altruism, self-sacrifice, and self-restraint, which will stimulate both evolutionary psychologists and psychoanalysts in their striving for a deeper and unified understanding of human nature.