It's amazing how sometimes my conversations overlap. Here's a quote from an email I got from my sister, Kate, recently. She's in Vet school. I find this topic fascinating -- hopefully some of you will also enjoy this.
>> Testosterone plays a major role in aggressive behavior and I don't
>> think there's any question that males tend to be more aggressive than
>> females (unless the female is protecting young). We routinely castrate the
>> males of most of our domestic species because they are too aggressive (and
>> too smelly).
>How does castration affect their smell?
Testosterone acts on the secondary sex glands of the males of many
eg: cats, goats (intact bucks really smell bad), ferrets, and others. These glands then produce secretions loaded with pheromones that act as olfactory signals to other members of their species.
>> Body builders who inject anabolic steroids (testosterone) turn
>> yellow (because they're damaging their livers), break out with acne, and
>> experience episodes of rage.
>Well, I'd certainly experience episodes of rage if I turned yellow and
>broke out in acne! But that's interesting -- I didn't know that
>steriods were related to testosterone. Are they really the same thing,
>or just closely related? Does pure testosterone have the muscle and
>performance enhancing characteristics of steroids?
Steroids are any of the cholesterol derived hormones in the body
testosterone, estrogen and corticosteroids. The term "steroids" is usually
used to mean corticosteroids which in the body are produced by the adrenal
gland and exogenously are used to control inflammation and produce immunosuppression (to treat autoimmune diseases or prevent organ transplant
rejection). Corticosteroids are catabolic steroids which means they cause a
breakdown of muscle and increased fat deposition. Testosterone is an anabolic steroid and it encourages growth of bone and muscle. A synthetic
form is available and is a controlled substance. This is the substance the
body builders abuse.
>> There are certainly other factors that
>> influence a tendency toward aggression, as violence can be seen in castrated
>> animals and females as well, but hormones certainly are a major contributor.
>> I think when one compares humans and other species on a population level
>> the similarities in this regard are striking but I also think it is
>> important to note that there are differences in aggressive tendencies among
>> individuals within any mammalian species.
>The book "Demonic Males" focused on the Great Apes, and only
>mentioned other animal species. I'd be interested to know if the myth
>about ours being the only species that murders our own kind is not just
>not true for the great apes, but also not true for other animals. That
>is, do animals other than the great apes also murder their own kind?
Absolutely. A male lion who takes over a pride immediately kills all
cubs sired by the previous male. This behavior has also been noted in colonies of domestic feral cats. Packs of dogs sometimes gang up and kill a
weak or injured member of the pack. Mice in confinement frequently kill
I have to go read about diseases of the cornea now.
-- Chris Maloney http://www.chrismaloney.com "Knowledge is good" -- Emil Faber