Read about the latest research published in Psychological Science.
Vít Třebický, Jan Havlíček, S. Craig Roberts, Anthony C. Little, and Karel Kleisner
Past research has suggested that people can use facial cues to predict men’s physical strength and fighting ability, but there is currently no direct evidence for this link. When participants rated pictures of mixed-martial-arts fighters for perceived aggressiveness and fighting ability, the researchers found that the perceived aggressiveness of fighters’ faces was associated with the fighters’ level of success in Ultimate Fighting Championship matches. The researchers hypothesize that humans’ sensitivity to facial cues associated with aggression and fighting ability may have arisen from an evolutionary adaptation to avoid dangerous physical confrontations with others.
Assaf Kron, Ariel Goldstein, Daniel Hyuk-Joon Lee, Katherine Gardhouse, and Adam Keith Anderson
Researchers have long believed that arousal and valence, two subjective properties underlying emotional experience, arise from distinct sources of emotional feelings. Does this distinction arise from a true disassociation or from limitations in how emotion is measured? Participants rated their level of valence and arousal in response to several images. Valence was reported using one bipolar scale or two unipolar scales. Valence and arousal were only dissociable when a bipolar valence scale was used, suggesting that observed distinctions between these two qualia may reflect measurement methods rather than differences in underlying emotional experiences.
Daniel A. Briley and Elliot M. Tucker-Drob
Past research has shown that genetic influences on cognitive ability increase across development; however, the mechanisms underlying these increases are not well understood. The researchers conducted a meta-analysis using 16 longitudinal studies that contained data from monozygotic, dizygotic, and adoptive siblings. They found that innovative genetic influences — the activation of genes not previously affecting cognitive ability — accounted for increases in heritability early in life, but by age 8, heritability increases were caused primarily by the amplification of existing genetic influences.
Yiyuan Li, Hong Li, Jean Decety, and Kang Lee
Research examining altruism has shown that people generally give to others in need, but most of these studies have been conducted with affluent populations. Are people still altruistic when they are the ones who need help? The researchers collected data on altruistic behavior from children living in China before and after experiencing an 8.0 magnitude earthquake. Younger children became more selfish immediately after the earthquake, whereas older children became more altruistic. The increase in giving in older children was related to their higher level of empathy for others, suggesting that both environmental insults and empathy play crucial roles in human altruism.