Saturday, December 23, 2006

Culture and climate

Brandeis historian David Hackett Fischer pointed out in his famous Albion's Seed that racial differences had an enormous impact on the history of America. He notes that the cold climate of colonial Massachusetts

"proved to be exceptionally dangerous to immigrants from tropical Africa, who suffered severely from pulmonary infections in New England winters. Black death rates in colonial Massachusetts were twice as high as whites' - a pattern very different from Virginia where mortality rates for the two races were not so far apart, and still more different from South Carolina where white death rates were higher than those of blacks. So high was mortality among African immigrants in New England that race slavery was not viable on a large scale, despite many attempts to introduce it. Slavery was not impossible in this region, but the human and material costs were higher than many wished to pay. A labor system which was fundamentally hostile to the Puritan ethos of New England was kept at bay partly by the climate."

Not surprisingly, in the 19th Century, Massachusetts became the home of abolitionism. South Carolina became the home of secession.

Friday, December 15, 2006

Masculinity and Perceived Status by Females

Physical Strength in Men Correlates with Attractiveness
Am J Hum Biol. 2006 Dec 7;19(1):82-87

Male facial appearance signals physical strength to women. Fink B, Neave N, Seydel H.Previous studies showed that male faces with extreme features that are likely to be associated with testosterone (T) are perceived as dominant and masculine. Women were reported to prefer masculinized male faces, as they may consider T markers to be an "honest" indication of good health. [and a holdover from the days when physical strength equated with status and leadershipTOM]

However, it is also likely that female preferences for certain male faces arise from the fact that dominant-and masculine-looking males are signaling characteristics which maybe beneficial in intrasexual conflict, and thereby also indicate potential achievers of high status, an important factor in female mate selection.

Although numerous studies were built on this assumption, nothing is known about the relationship between perceived facial dominance and physical strength in men. We measured hand-grip strength, as a measure of overall physical strength, in a sample of 32 male students, and recorded age, body weight, and height. Seventy-nine women rated facial images of these men for dominance, masculinity, and attractiveness.

After controlling for age and bodyweight, hand-grip strength was found to correlate significantly positively with all three measures. The present data thus support the supposition that a male's physical strength is also signaled via facial characteristics of dominance and masculinity, which are considered attractive by women.

Saturday, December 02, 2006

Gene Variant in Abused Boys Linked to Antisocial Behavior

by Joan Arehart-Treichel

When maltreatment is combined with having the short MAOA gene variant, it may put children on track for antisocial behavior later on. Genetic screening, however, may not be a strategy for preventing such behavior.

For four years, the case has been building that a short variant of the monoamine oxidase a (MAOA) gene, when combined with harsh discipline, physical abuse, or other forms of maltreatment, puts youngsters at risk for antisocial behavior.

In 2002, as noted in an earlier post, Avshalom Caspi, Ph.D., of the Institute of Psychiatry in London and his coworkers were the first to report such a connection in a sample of more than 400 young men who had been followed since childhood. In 2004, Debra Foley, Ph.D., an assistant professor of human genetics at Virginia Commonwealth University, and colleagues reported that they had made the same association in youth aged 8 to 17 (Psychiatric News, September 3, 2004). And now Julia Kim-Cohen, Ph.D., an assistant professor of psychology at Yale University, and her team have reported the association once again, but in 7-year-old children. They published their findings in the October Molecular Psychiatry.

This latest inquiry included 975 boys. At ages 5 and 7, the boys had DNA samples taken and were assessed for physical mal-treatment, such as fractures, dislocations, or being burned with matches. The scientists then looked to see whether boys who had been physically abused and possessed the short variant of the MAOA gene (16 subjects) had significantly greater mental health problems than did boys who had been physically abused and possessed the long variant of the gene (46 subjects). This turned out to be the case.

The researchers then classified the mental health problems into emotional difficulties, antisocial behavior, or attention and hyperactivity difficulties. Again they found that children who possessed the short MAOA gene version and who had been exposed to physical abuse had more emotional problems, more antisocial behavior, and more attention and hyperactivity difficulties than did those children with the long gene version who had been abused. However, only the attention-hyperactivity results yielded a clear statistical significance.

Source: Psychiatry News