Department of Psychology

Harriet M. Wall Lecture Series



Which is the frail sex?

Understanding sex differences in mortality rates

with an evolutionary life history framework


presented by

Daniel J. Kruger, Ph.D.

School of Public Health and Institute for Social Research
University of Michigan


Sex differences in mortality rates result from genetic, physiological, behavioral, social, and environmental causes that are best understood when integrated into an evolutionary life history framework. This presentation depicts how sex differences in mortality rates across age and cause can be understood in the context of life history allocation of somatic and reproductive efforts. Excess male mortality is a result of a trade-off between competitiveness and longevity. Social and environmental conditions intensifying male competition for resources, status, and mates lead to increased male mortality through riskier behavior patterns and the impact of stress on physiological susceptibility. The fact that sex differences in mortality rates are not genetically determined encourages intervention efforts to reduce excess male mortality. These patterns confirm our expectations derived from evolutionary theory and are consistent with the notion that sex differences shaped by sexual selection interact with aspects of the current environment to result in mortality rates considerably higher for men than for women across the lifespan. These findings have important implications for behavioral and health patterns. The sex difference in mortality rates is an important indicator of life history and social conditions.


Wednesday, March 19, 2014

3:00 PM

University Center KIVA


All interested persons are cordially invited.  Light refreshments will be offered.
For further information, please contact or phone (810) 762-3424.