Taking an approach that emphasizes the evolutionary underpinnings of social behavior, Buss, a professor of psychology, analyzed the results of a survey in many countries around the world of what men and women desire in mates. These preferences are often thought to be culturally determined. He found consistent preferences among men for younger women and among women for men older than themselves. He explains this by suggesting the survival advantage that would confer on children. Younger women appear healthy, which would be interpreted as an ability to bear children.
Older men appear capable of helping the women garner the resources needed to raise a child.
Thus, the desire for mates with these characteristics would evolve through the ages in the same way that humans evolved a taste for foods that were safe to eat and provided needed nutrients. Nearly half of all Americans between the ages of 15 and 54 have experienced an episode of a psychiatric disorder at some time in their lives, and nearly 30 percent have had one in the last year, according to the first national survey to administer psychiatric interviews to a sample of the general population. Sociologist Ron Kessler was the principal investigator for the study, conducted by the Institute for Social Research. The most common disorders identified were major depression and alcohol dependence. Drug Use by Young Adults Rising Drug use among American young people has been making a clear comeback in the last two years, according to UM research scientists Lloyd Johnston , Patrick O'Malley , and Jerald Bachman of the Institute for Social Research.