Fathers Reduce Mating To Care Offsprings

[thinker_jeff]

Here is the news:

 

Longitudinal evidence that fatherhood decreases testosterone in human males

 

In species in which males care for young, testosterone (T) is often high during mating periods but then declines to allow for caregiving of resulting offspring. This model may apply to human males, but past human studies of T and fatherhood have been cross-sectional, making it unclear whether fatherhood suppresses T or if men with lower T are more likely to become fathers. Here, we use a large representative study in the Philippines (n = 624) to show that among single nonfathers at baseline (2005) (21.5 ± 0.3 y), men with high waking T were more likely to become partnered fathers by the time of follow-up 4.5 y later (P < 0.05). Men who became partnered fathers then experienced large declines in waking (median: −26%) and evening (median: −34%) T, which were significantly greater than declines in single nonfathers (P < 0.001). Consistent with the hypothesis that child interaction suppresses T, fathers reporting 3 h or more of daily childcare had lower T at follow-up compared with fathers not involved in care (P < 0.05). Using longitudinal data, these findings show that T and reproductive strategy have bidirectional relationships in human males, with high T predicting subsequent mating success but then declining rapidly after men become fathers. Our findings suggest that T mediates tradeoffs between mating and parenting in humans, as seen in other species in which fathers care for young. They also highlight one likely explanation for previously observed health disparities between partnered fathers and single men.

http://www.pnas.org/...9/02/1105403108

 

My question is - is this result related with the culture? Why they do this in Philippines?

Edited September 19, 2011 by thinker_jeff

[amanda more]

Here is the news:

 

Longitudinal evidence that fatherhood decreases testosterone in human males

 

In species in which males care for young, testosterone (T) is often high during mating periods but then declines to allow for caregiving of resulting offspring. This model may apply to human males, but past human studies of T and fatherhood have been cross-sectional, making it unclear whether fatherhood suppresses T or if men with lower T are more likely to become fathers. Here, we use a large representative study in the Philippines (n = 624) to show that among single nonfathers at baseline (2005) (21.5 ± 0.3 y), men with high waking T were more likely to become partnered fathers by the time of follow-up 4.5 y later (P < 0.05). Men who became partnered fathers then experienced large declines in waking (median: −26%) and evening (median: −34%) T, which were significantly greater than declines in single nonfathers (P < 0.001). Consistent with the hypothesis that child interaction suppresses T, fathers reporting 3 h or more of daily childcare had lower T at follow-up compared with fathers not involved in care (P < 0.05). Using longitudinal data, these findings show that T and reproductive strategy have bidirectional relationships in human males, with high T predicting subsequent mating success but then declining rapidly after men become fathers. Our findings suggest that T mediates tradeoffs between mating and parenting in humans, as seen in other species in which fathers care for young. They also highlight one likely explanation for previously observed health disparities between partnered fathers and single men.

http://www.pnas.org/...9/02/1105403108

 

My question is - is this result related with the culture? Why they do this in Philippines?

 

I think one way to think of this is the ritual fighting that birds etc. go through during mating times in order to get access to females. T needs to be high for that. Although T is higher in males than females it is not the sum total of male identity. Human culture is a cooperative herd tribe evolutionary progression. Continued high testosterone in many species would be counterproductive to that. A continuous high 'roid human would have trouble hanging out with the tribe. So higher and higher steroid males would not have been selected for. In apes in order to get a female to get fertile and get busy a male can kill the baby she is holding in order to make her available. That is not the baby's father.

 

Single males may also be considered more expendable. They are famous for risk taking. Out on the hunt they may help the tribe out. So higher Testosterone helps the tribe get more meat. Once they start fathering then that and home tribal activity becomes important also and risk taking more problematic for his mate and the tribe.

 

I doubt this has anything to do with the Phillippines only.

 

Men often assume women go for the biggest,strongest most buff guy. Yet they are continually puzzled with the choices women actually make. In order to coexist high 'roid is counterproductive for a relationship especially. A crying baby is a stress that needs a different chemical mix to have a chance to handle.