Wednesday, November 14, 2007


Dr. Giddings has recently posted on her bailiwick, gender issues (here and here) . Though its not exactly my area of study, I'm always interested in research on gender differences. I'm incredibly lucky to have a colleague like Lisa who will thoughtfully discuss these issues and not react the way Harvard's faculty did to Larry Summer's musings on gender. So with that preface I'll share some controversial recent research. The first piece, by Cawley and Liu , use time use data to identify the source of maternal employment's impact on increasing childhood obesity.
Recent research has found that maternal employment is associated with an increased risk of childhood obesity. This paper explores mechanisms for that correlation. We estimate models of instrumental variables using a unique dataset, the American Time Use Survey, that measure the effect of maternal employment on the mother’s allocation of time to activities related to child diet and physical activity. We find that employed women spend significantly less time cooking, eating with their children, and playing with their children, and are more likely to purchase prepared foods. We find suggestive evidence that these decreases in time are only partly offset by husbands and partners. These findings offer plausible mechanisms for the association of maternal employment with childhood obesity.
The second, by Noam Kirson, concerns how female labor force participation shortens the life of their male spouses.
This paper finds a strong positive correlation between female labor force participation and negative health outcomes for middle-aged men and women, and suggests that this correlation is mediated by household-level stress. At the cross-country aggregate level, I show that labor force participation of women is associated with increased mortality rates among both men and women. At the individual level, I find that married men whose spouses work are more likely to die within 10 years, to have high blood pressure and to self-report worse health outcomes. The findings do not appear to be the result of reverse causality. The mortality effects, both aggregate and individual, are especially large for deaths from ischemic heart disease, while weak to moderate for cancer. These findings match well with the medical evidence on the link between stress and health.
Of course this isn't the only mechanism by which women can shorten men's lives. They also "make" us do stupid, crazy things. Don't forget male life expectancy is much shorter than women's due largely to the increased likelihood of death from accident. We are the risk takers, and I mean that in the physical sense. From The Economist:
Chasing females can take years off life

IN THE cause of equal rights, feminists have had much to complain about. But one striking piece of inequality has been conveniently overlooked: lifespan. In this area, women have the upper hand. All round the world, they live longer than men. Why they should do so is not immediately obvious. But the same is true in many other species. From lions to antelope and from sea lions to deer, males, for some reason, simply can't go the distance.

One theory is that males must compete for female attention. That means evolution is busy selecting for antlers, aggression and alloy wheels in males, at the expense of longevity. Females are not subject to such pressures. If this theory is correct, the effect will be especially noticeable in those species where males compete for the attention of lots of females. Conversely, it will be reduced or absent where they do not.
The best thing I have read on the evolutionary psychology/biology of gender differences is this speech by Roy F. Baumeister (here). Read and discuss, preferably with the opposite sex and preferably in a room without sharp objects.

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