Costly retaliation is promoted by threats to resources in women and threats to status in men.

What motivates people to act against their own self-interest? In men, what seems to be irrational decision-making in the short-term may be explained by other long-term benefits; thus retaliation may not be motivated by tangible costs, but instead intangible psychological variables (e.g., status threats). In contrast, there is evidence that women are more sensitive to tangible costs than are men. In Experiment 1, using the Point Subtraction Aggression Paradigm (PSAP), we tested the prediction that in men, the frequency of provocation, and not the monetary loss (tangible cost), would be associated with retaliation, whereas women would be sensitive to the tangible costs. In keeping with the prediction, women (n = 80) who incurred greater tangible costs (irrespective of frequency) retaliated with more costly punishment, whereas men (n = 90) who were provoked more frequently (irrespective of tangible costs) retaliated with more costly punishment. In Experiment 2, we directly investigated whether women were more sensitive to threats to resources and men were more sensitive to threats to status, as suggested by the results of Experiment 1. Women's (n = 53) retaliation was greater when they reported it to be a means to protect their resources, and men's (n = 35) retaliation was greater when they reported it to be a means to protect their status. Thus, these results identify psychological variables that guide retaliation that is costly to the actor. Consistent with evolutionary perspectives, concerns about status appear to drive costly retaliatory behavior more so in men than in women.

Facing aggression: cues differ for female versus male faces.

The facial width-to-height ratio (face ratio), is a sexually dimorphic metric associated with actual aggression in men and with observers' judgements of aggression in male faces. Here, we sought to determine if observers' judgements of aggression were associated with the face ratio in female faces. In three studies, participants rated photographs of female and male faces on aggression, femininity, masculinity, attractiveness, and nurturing. In Studies 1 and 2, for female and male faces, judgements of aggression were associated with the face ratio even when other cues in the face related to masculinity were controlled statistically. Nevertheless, correlations between the face ratio and judgements of aggression were smaller for female than for male faces (F(1,36) = 7.43, p = 0.01). In Study 1, there was no significant relationship between judgements of femininity and of aggression in female faces. In Study 2, the association between judgements of masculinity and aggression was weaker in female faces than for male faces in Study 1. The weaker association in female faces may be because aggression and masculinity are stereotypically male traits. Thus, in Study 3, observers rated faces on nurturing (a stereotypically female trait) and on femininity. Judgements of nurturing were associated with femininity (positively) and masculinity (negatively) ratings in both female and male faces. In summary, the perception of aggression differs in female versus male faces. The sex difference was not simply because aggression is a gendered construct; the relationships between masculinity/femininity and nurturing were similar for male and female faces even though nurturing is also a gendered construct. Masculinity and femininity ratings are not associated with aggression ratings nor with the face ratio for female faces. In contrast, all four variables are highly inter-correlated in male faces, likely because these cues in male faces serve as "honest signals".

Repeat organization and epigenetic regulation of the DH-Cmu domain of the immunoglobulin heavy-chain gene locus.

The first steps of murine immunoglobulin heavy-chain (IgH) gene recombination take place within a chromosomal domain that contains diversity (D(H)) and joining (J(H)) gene segments, but not variable (V(H)) gene segments. Here we show that the chromatin state of this domain is markedly heterogeneous. Specifically, only 5'- and 3'-most D(H) gene segments carry active chromatin modifications, whereas intervening D(H)s are associated with heterochromatic marks that are maintained by ongoing histone deacetylation. The intervening D(H)s form part of a tandemly repeated sequence that expresses tissue-specific, antisense oriented transcripts. We propose that the intervening D(H) genes are actively suppressed by repeat-induced epigenetic silencing, which is reflected in their infrequent representation in DJ(H) junctions compared to the flanking D(H) genes.