Testicle Size and Fatherly Interactions

[Paolo]

http://www.bbc.co.uk/news/health-24016988?print=true

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9 September 2013 Last updated at 20:28 ET Testicle size 'link to father role'

Comments (220) (http://www.bbc.co.uk/news/health-240169 ... a-comments)

A link between the size of a father's testicles and how active he is in bringing up his children has been suggested by scientists.

Researchers at Emory University, US, said those with smaller testicles were more likely to be involved with nappy changing, feeding and bath time.

They also found differences in brain scans of fathers looking at images of their child, linked to testicle size.

But other factors, such as cultural expectations, also played a role.

Levels of promiscuity and testicle size are strongly linked in animals, those with the largest pair tending to mate with more partners.

The researchers were investigating an evolutionary theory about trade-offs between investing time and effort in mating or putting that energy into raising children. The idea being that larger testicles would suggest greater commitment to creating more children over raising them.

The study, in Proceedings of the National Academy of Science (http://www.pnas.org/cgi/doi/10.1073/pnas.1305579110), looked at the relationship between testicle size and fatherhood in 70 men who had children between the ages of one and two.

The team at Emory University in Atlanta performed brain scans while the men were shown pictures of their children.

It showed those with smaller testicles tended to have a greater response in the reward area of the brain than those with a larger size.

MRI scans showed a three-fold difference between the volumes of the smallest and largest testicles in the group.

Those at the smaller end of the spectrum were also more likely, according to interviews with the man and the mother, to be more active in parenting duties.

One of the researchers, Dr James Rilling, told the BBC: "It tells us some men are more naturally inclined to care-giving than others, but I don't think that excuses other men. It just might require more effort for some than others."

The exact nature of any link is not clear.

The researchers believe the size of the testicles, probably through the hormone testosterone, is affecting behaviour. But it is not clear if the process of having a baby may have some effect on the father.

"We know, for instance, that testosterone levels go down when men become involved fathers," said Dr Rilling.

Further studies, involving analysing the size before and after becoming a father, are still needed.

Cultural and societal expectations on the role of the father are also not accounted for in the study.

All of the men were from the Atlanta area so the relative impact of society and biology has not been measured.

[DeaconBlues (imported)]

DAMN! You beat me to it! I heard this story last night on BBC and just knew I wanted to post it here just as soon as I got off shift, and I see I am not the only one who finds this very interesting.

I believe the researchers are "sandbagging" things a bit (I think they are holding back, not saying something they do already know), when they say things like "t

he exact nature of any link is not clear...

" Uh-huh, sure... yeah... I am not even a scientist and I am seeing some pretty clear links, and I am coming up with some pretty good ideas. But of course, I (and everyone else here at EA) am clearly biased, still, bias or not, it seems pretty clear to me that the best "father" behavior is linked to the lowest testosterone levels. To put in bluntly, the best biological father (the one who gets a woman pregnant and is most likely to sire healthy children) and the best "father" (the one who actually cares for and raises the child) are NOT the same person, that may be "politically incorrect" and "un-Christian" and a lot of other things too, but it is something I have suspected for a long long time.

[DeaconBlues (imported)]

Now that I think about it, there was another bit of news last night on BBC that was almost as interesting as the bit on testicle size and father behavior. There was another news item about how men are becoming much less adventurous, but women are not. Some survey study, done over the last four or five decades, shows that fewer and fewer men are showing interest in risky adventurous behavior (e.g. mountaineering, skydiving, etc.) but at the same time women are NOT showing any decrease, no significant increase, but when compared with the diminishing interest in risk taking behavior in the male population, that fact that there is no decrease in the female population is very interesting. Does this issue merit another discussion thread?

[Losethem (imported)]

So if you are male and don't have testicles, does this mean you're so involved you're breast feeding?

--LT

[Wellesley (imported)]

I have long thought that environmental toxins have effected hormones.

I tend to think that men in the modern era have much, much less T than those even 100 years ago.

Or is it because the lifestyle has changed so much that having too much T is actually a problem for most men who are not in the "alpha male" group.

Having no testicles changes thinking a lot I think. Even with T replacement.

[Paolo]

It's been my experience that men with a lot of testosterone as almost always the ones to say "I hate kids!" and kids don't like them, either.

Back in the day, I can offer the example of my uncle and grandfather. Then there was my adult friend, a totally different character.

Then along came my stepfather.

No wonder I grew up identifying as "Not Male."

[hazbalz (imported)]

I have long thought that environmental toxins have effected hormones.

I tend to think that men in the modern era have much, much less T than those even 100 years ago.

Or is it because the lifestyle has changed so much that having too much T is actually a problem for most men who are not in the "alpha male" group.

Having no testicles changes thinking a lot I think. Even with T replacement.

I have a friend who theorizes that today's males have less testosterone and more estrogen in their systems due to hormones given to cattle, which we then consume in our steaks and burgers.

[tugon (imported)]

My father must have had big ones from all the beating and cheating he did. Of course the verbal abuse and fighting with my mother was always a good time. One night I heard him shout I never wanted those damn kids anyway. If my childhood was not so repressed I could remember there size. Ya he must have had big ones.

[tugon (imported)]

I have long thought that environmental toxins have effected hormones.

I tend to think that men in the modern era have much, much less T than those even 100 years ago.

Or is it because the lifestyle has changed so much that having too much T is actually a problem for most men who are not in the "alpha male" group.

Having no testicles changes thinking a lot I think. Even with T replacement.

Dr. Oz was talking about how soybeans are processed. If the whole bean is not used what is left is the estrogen. He showed how to check if the whole bean is used but I am unable to recall how.

[Wellesley (imported)]

My father must have had big ones from all the beating and cheating he did. Of course the verbal abuse and fighting with my mother was always a good time. One night I heard him shout I never wanted those damn kids anyway. If my childhood was not so repressed I could remember there size. Ya he must have had big ones.

I hear that. I assume my father had huge ones. Either actually or just in his mind. Maybe the most abusive fathers are over compensating though?

Hmmm..... Makes me think of a whole other topic now though.