The sexual behavior shortens a man's life

Jun 20, 2007 18:26 GMT  ·  By

"Live fast, die young" seems to be the motto of all males on the planet. The fact that women live, on average, longer is an ancient and universal fact. "Women live longer in almost every country, and the sex difference in lifespan has been recognized since at least the mid-18th century. It isn't a recent trend; it originates from our deep evolutionary history. This skewed mortality isn't even unique to our species; the men come up short in common chimps and many other species", said Daniel J. Kruger, a research scientist in the University of Michigan School of Public Health and the Institute for Social Research.

He and co-author Randolph Nesse, professor of psychology and psychiatry and director of the Evolution and Human Adaptation Program, showed that sexual behavior is what shortens a male's life. "This whole pattern is a result of sexual selection and the roles that males and females play in reproduction. Females generally invest more in offspring than males and are more limited in offspring quantity, thus males typically compete with each other to attract and retain female partners." said Kruger.

Researches showed that in chimps - humans' closest species - the highest mortality rate difference between the genders takes place at about 13 years of age, when males get sexually mature, starting the aggressive struggle for social status and females. From the peacock tail to pimp clothes in men, males compete fiercely for attracting females, and this comes at a price.

"In nature, it means riskier physiology and behavior for the males, such as putting more resources into flashy plumage or engaging in physical sparring. And even in modern life, where most dueling is a form of entertainment, male behavior and physiology is shortening their lifespans relative to women," said Kruger.

Moreover, modern lifestyles actually enlarges the male-female mortality differences. "Male physiology, shaped by eons of sexual competition, is putting the guys at a disadvantage in longevity. Male immune systems are somewhat weaker, and their bodies are less able to process the fat they eat," said Kruger.

Their behavioral instability makes men more prone to drinking, drug consume, smoking, overeating, reckless driving, violence, factors known to shorten the life expectancy. "Because mortality rates in general are going down, behavioral causes of death are ever more prevalent. Males who have a relatively lower status or lack a mate engage in a riskier pattern of behaviors in an attempt to get ahead," added Kruger.