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Institutional review boards (IRBs) have expressed concerns that certain individuals or groups, such as participants who are younger, ethnic minorities, or who have certain psychological or personality traits, may be particularly distressed when participating in "sensitive topics" research. This study examined the effects of several demographic and individual difference factors (i.e., age, sex, ethnicity, religiosity, Big Five personality traits, and baseline psychological distress levels) on reactions to participation in sensitive topics research. Participants were 504 undergraduates who completed an extensive battery of either trauma/sex questionnaires or cognitive tests and rated their positive and negative emotional reactions and the perceived benefits and mental costs of participating. They also compared research participation to normal life stressors. Our findings indicated that individual difference and demographic risk factors do not increase participant distress after participating in sex/trauma research over and above that experienced after participating in traditionally minimal-risk cognitive tasks. Participants generally found research participation less distressing than normal life stressors and even enjoyable.

Most theories of human mental evolution assume that selection favored higher intelligence and larger brains, which should have reduced genetic variance in both. However, adult human intelligence remains highly heritable, and is genetically correlated with brain size. This conflict might be resolved by estimating the coefficient of additive genetic variance (CVA) in human brain size, since CVAs are widely used in evolutionary genetics as indexes of recent selection. Here we calculate for the first time that this CVA is about 7.8, based on data from 19 recent MRI studies of adult human brain size "in vivo": 11 studies on brain size means and standard deviations, and 8 studies on brain size heritabilities. This CVA appears lower than that for any other human organ volume or life-history trait, suggesting that the brain has been under strong stabilizing (average-is-better) selection. This result is hard to reconcile with most current theories of human mental evolution, which emphasize directional (more-is-better) selection for higher intelligence and larger brains. Either these theories are all wrong, or CVAs are not as evolutionarily informative as most evolutionary geneticists believe, or, as we suggest, brain size is not a very good index for understanding the evolutionary genetics of human intelligence.

Madole & Harden develop some good ideas about how to understand genetic causality more clearly, but they frame the benefits of behavior genetics research at a largely collective level, focused on the pros and cons of different ways to engineer the gene pool or social behavior. This neglects the individual benefits of hereditarian insights for mate choice and parenting. [ABSTRACT FROM AUTHOR]

The relationship between ethnicity and biology is of interest to anthropologists, biomedical scientists, and historians in understanding how human groups are constructed. Ethnic self-identification in recently admixed groups such as Hispanics, African Americans, and Native Americans (NA) is likely to be complex due to the heterogeneity in individual admixture proportions and social environments within these groups. This study examines the relationships between self-identified ethnicity, self-estimated admixture proportions, skin pigmentation, and genetic marker estimated admixture proportions. These measures were assessed using questionnaires, skin color measurements, and genotyping of a panel of 76 ancestry informative markers, among 170 Hispanics and NAs from New Mexico, a state known for its complex history of interactions between people of NA and European (EU) ancestry. Results reveal that NAs underestimate their degree of EU admixture, and that Hispanics underestimate their degree of NA admixture. Within Hispanics, genetic-marker estimated admixture is better predicted by forehead skin pigmentation than by self-estimated admixture. We also find that Hispanic individuals self-identified as 'half-White, half Hispanic' and 'Spanish' have lower levels of NA admixture than those self-identified as 'Mexican' and 'Mexican American.' Such results highlight the interplay between culture and biology in how individuals identify and view themselves, and have implications for how ethnicity and disease risk are assessed in a medical setting. KEY WORDS ethnic identity; New Mexico; genetic ancestry

Conspicuous displays of consumption and benevolence might serve as 'costly signals' of desirable mate qualities. If so, they should vary strategically with manipulations of mating-related motives. The authors examined this possibility in 4 experiments. Inducing mating goals in men increased their willingness to spend on conspicuous luxuries but not on basic necessities. In women, mating goals boosted public--but not private--helping. Although mating motivation did not generally inspire helping in men, it did induce more helpfulness in contexts in which they could display heroism or dominance. Conversely, although mating motivation did not lead women to conspicuously consume, it did lead women to spend more publicly on helpful causes. Overall, romantic motives seem to produce highly strategic and sex-specific self-presentations best understood within a costly signaling framework. Key words: costly signaling, altruism, conspicuous consumption, mating goals, self-presentation

Seventy-eight young males were tested by measuring their left-right symmetry at 10 body points, and by administering five cognitive tests with diverse g-loadings. Results indicated that there is substantial overlap between morphodevelopmental stability and neurodevelopmental stability.

Studies of visual apparent motion have relied on observers' subjective self-reports of experienced motion, for which there is no objective criterion of right or wrong. A new method of phase discrimination is reported that may offer an objective indicator of apparent motion. Ss discriminated the direction of an objective 75-ms phase shift, away from strict temporal alternation of 2 stimulus dots. Accuracy increased from 50% to 100% correct as rate of alternation and distance between the dots was decreased, in conformity with Korte's third law of apparent motion. This and additional evidence suggests that phase discrimination may be mediated by asymmetries between the experienced strengths of leftward and rightward motion. Phase discrimination may also be adaptable to the study of apparent motion and related phenomena in other sensory modalities and other animal species.