Fatherhood Decreases Testosterone

[pokerfan]

ScienceNow
by Elizabeth Norton
12 September 2011, 3:01 PM

Humans are probably the only species on Earth who nurture their young for 20 years or more. For men in particular, the intensive demands of parenting can come as such a shock that a built-in biological mechanism has evolved to help cope with the change. A new study shows that becoming a father leads to a sharp decline in testosterone, suggesting that although high levels of the hormone may help men win a mate, testosterone-fueled traits such as aggression and competition are less useful when it comes to raising children.

Previous research had shown that among new fathers, testosterone levels were lower than in men of the same age who didn't have children. But no study addressed whether parenthood itself was responsible, or whether men who became committed partners and fathers started out with lower levels of the hormone than did their single, footloose friends.

To sort out cause and effect, anthropologists Lee Gettler, Christopher Kuzawa, and colleagues at Northwestern University in Evanston, Illinois, and the University of San Carlos in Cebu City, Philippines, checked testosterone levels in a group of men participating in the ongoing Cebu Longitudinal Health and Nutrition Survey. The survey began with a group of some 3000 women who were pregnant in 1983 and followed the general health, nutrition, medical care, and survival of their children; it has since expanded into an intergenerational study of health, education, and sexual behavior as those children grew up and are now having children of their own.

More: http://news.sciencemag.org/sciencenow/2011/09/fatherhood-decreases-testosteron.html

[Ilsa]

1. Wow. Fascinating longitudinal study!

I sent this to my friend who is a marriage & family counselor.

[dtexdem]

2. Yet another argument for allowing Catholic priests to marry.

;-)

[pokerfan]

5. on the other hand

A celibate clergy is an especially good idea, because it tends to suppress any hereditary propensity toward fanaticism. (Carl Sagan)

[xchrom]

3. Interesting. Nt

[pokerfan]

4. someone posted a picture of their test subject

over on io9:

[jberryhill]

6. You know why?

Show me the father whose wriggling toddler (including both of my own) hasn't kicked him in the relevant organs.

My youngest got me there with a paint ball gun!

[Odin2005]

7. Put this in to the "No Duh" column, IMO

A drop in testosterone levels after a guy becomes a father seems very reasonable from an evolutionary POV. it would decrease the risk of both adultery and domestic violence.

[AlecBGreen]

8. BUUUUT...

what about the necessary agression to defend your new family?

Im wondering if this isnt a recent (100 years) phenomenon. Perhaps its caused by environmental factors and not a built-in trait of the human race.

[semillama]

9. Does anyone know if testosterone levels correlate to adequate sleep?

Because, you know.