Wednesday, October 15, 2008

Why women breakdown; maybe it's agriculture?   posted by Razib @ 10/15/2008 02:41:00 AM

Why Do Women Get More Cavities Than Men?:
"The role of female-specific factors has been denied by anthropologists, yet they attain considerable importance in the model proposed here, because the adoption of agriculture is associated with increased sedentism and fertility," Lukacs said. "I argue that the rise of agriculture increased demands on women's reproductive systems, contributing to an increase in fertility that intensified the negative impact of dietary change on women's oral health. The combined impacts of increased fertility, dietary changes and division of labor during the move into agricultural societies contributed to the widespread gender differential observed in dental caries rates today."

The original paper is Fertility and Agriculture Accentuate Sex Differences in Dental Caries Rates:
The transition from foraging to farming is associated with a widespread and well-documented decline in oral health, wherein women experience a more rapid and dramatic decline than men. Historically, anthropologists have attributed this difference to behavioral factors such as sexual division of labor and gender-based dietary preferences. However, the clinical and epidemiological literature on caries prevalence reveals a ubiquitous pattern of worse oral heath among women than men. Research on cariogenesis shows that women's higher caries rates are influenced by changes in female sex hormones, the biochemical composition and flow rate of saliva, and food cravings and aversions during pregnancy. Significantly, the adoption of agriculture is associated with increased sedentism and fertility. I argue that the impact of dietary change on women's oral health was intensified by the increased demands on women's reproductive systems, including the increase in fertility, that accompanied the rise of agriculture and that these factors contribute to the observed gender differential in dental caries.

Honestly, my first thought was "maybe women just like sugar more?" In any case, one thing I assume is that the higher "fertility" of agricultural women is going to be due to the fact that they do not space their births. In contrast, hunter-gatherer women typically have a reduced number of pregnancies because ofbehaviors such as extended breastfeeding. Of course, most agricultural societies quickly reached the Malthusian limit (ecological carrying capacity), so the higher fertility was likely balanced out by higher infant mortality. If agricultural women gave birth to more infants a greater proportion of these offspring ended up dying of diseases, etc., than for hunter-gatherers. So at birth any given hunter-gatherer infant is far more likely to reach reproductive age than any given offspring of peasants....

Related: Group lifespan differences? Maybe it's agriculture, Maybe it's agriculture?, Demon rum, Maybe it's agriculture - soft sweep TRPV6, Maybe it's agriculture?, Maybe it's agriculture - skin color edition.... and Tall, to short, to tall (again).