Send letter to journal:
Re: What about male-female homicide ratio and male mortality rate?

Dear Editor,

In the article discussing the possible role of patriarchy itself in influencing male mortality, I would like to see two figures that I couldn't find: 1. the ratio of male to female homicide, and 2. male mortality rate broken down into homicides vs. all other causes. When murder rates are high for both men and women, it may be other factors than patriarchy at fault--such as war, high crime rates, civil strife, or post-disaster stress and crowding, as in refugee housing. (A separate but related question might be whether highly patriarchal attitudes increase the likelihood that men will "take it out on" women in conditions of stress.)

Send letter to journal:
Re: Human evolution as cause for patriarchy and mortality patterns

Dear Editor,

Stanistreet, Bambra, and Scott-Samuel’s article[1] on the connection between patriarchy and higher male mortality rates addresses issues which we are currently investigating, although with a very different theoretical framework. The universality of sex differences in mortality rates begs for a valid explanation that can account for both similarities and differences across diverse human cultures. We believe that human mortality patterns result from the interaction of features shaped by our evolutionary history of sexual selection and our developmental environment.[2] Briefly, because females (and especially human women) make a greater parental investment in offspring, they are more selective in choosing mating partners.[3] Males generally compete with each other for reproductive access to females3 and in humans this includes competing for social status and material resources, features that are much more important for males than females in attracting mates for across cultures.[4] Because humans are a mildly polygynous species (as evidenced by the degree of our physical sexual dimorphism5), throughout our evolutionary history some men have been able to obtain multiple partners at the expense of others. This skew in reproductive success creates an incentive for behavioural and physiological strategies that carry higher risks of early mortality in men than in women.

We believe that the Male to Female Mortality Ratio (M:F MR, the ratio of male to female mortality rates) may be a useful indicator of systematic characteristics of cultures, such as the severity of male-male competition, levels of political instability, and/or inequality in social status and control of resources.[6] In previous work, we found that the overall M:F MR across nations was inversely correlated with women's empowerment, as measured by the UN Gender Empowerment Measure, r(44) = -.654, p<.001. A stepwise linear regression including the GDP indicator from Stanistreet et al. found that gender empowerment accounted for 51% of the variance in M:F MR levels across nations, but did not find a unique contribution of GDP, F(1,39) = 41.16, p<.001. The UN Gender Empowerment Measure is a composite of the percentage of; members of parliament, legislators, senior officials and managers, professional and technical workers who are female; and the ratio of estimated female to male earned income. Although Stanistreet et al., note concerns with the reliability of some of these measures, error would most likely decrease the strength of the relationship found between gender empowerment and the M:F MR. We also find the inference of a causal relationship between social attributes and mortality solely from consistencies in mortality patterns to be somewhat tautological.

Our theoretical framework does not exclude a feminist perspective on or provide a moral justification for inequality, but it does provide an ultimate theoretical explanation for the widespread existence of both patriarchy and sex differences in mortality. Societies differ in the degree to which resources and power are held by elite men (which is probably related to various ecological and historical factors), and the degree to which the majority of women and men are dominated by elite men affects the intensity of male-male competition for this power. We have demonstrated elsewhere that the degree of socio-economic inequality both within and across nations is related to the M:F MR6,7. Our approach highlights interactions between adaptations developed during human evolutionary history and current environmental factors, so we can supercede the unproductive debates over the respective roles of biology and culture. Within and cross national differences in death rates demonstrate human flexibility and the potential for change as well as the importance of illuminating the causal framework for mortality patterns.

References

1 Stanistreet D, Bambra C, Scott-Samuel A. Is patriarchy the source of men’s higher mortality? J. Epidemiol. Community Health 2005;59:873-876.

2 Kruger D, Nesse R. Sexual selection and the Male:Female Mortality Ratio. Evolutionary Psychology 2004;2:66-77.

3 Trivers R. Parental investment and sexual selection. In: B. Campbell B ed. Sexual selection and the descent of man: 1871-1971 Chicago: Aldine, 1972:136-179.

4 Buss D. Sex difference in human mate preferences: Evolutionary hypotheses tested in 37 cultures. Beh Brain Sci 1989; 12:1-49.

5 Leutenegger W, Kelley J. Relationship of sexual dimorphism in canine size and body size to social, behavioral, and ecological correlates in anthropoid primates. Primates 1977;18:117-136.

6 Kruger D, Nesse R. Economic transition, male competition, and sex differences in mortality rates. Manuscript submitted for publication.