Health Tips for Thursday, March 30 By SHEILA STAVISH, UPI Science News

MALE HORMONES IN THE WOMB AND SEXUAL ORIENTATION: The level of male hormones, or androgens, in the womb may influence an unborn child's future sexual orientation, according to a study in the journal Nature. In fetal and in adult life, both males and females produce androgens, but the levels of the hormone are much lower in females. Scientists know that fetal androgen levels help shape the grown adult in more than the major, obvious ways. Curiously enough, a person's finger-length ratio is an indicator of how much androgen they were exposed to as a fetus. Specifically, the difference between the length of the index finger and ring finger on the right hand accords with gender. In women, these fingers are usually about the same length. In men, the index finger is generally shorter than the ring finger. Marc Breedlove, a professor of psychology at the University of California at Berkeley, found in a study that higher levels of fetal androgens -- as indicated by finger-length ratio -- may increase the odds for both males and females to develop a homosexual orientation. Breedlove collected data on 720 people who attended three San Francisco Bay Area street fairs in the fall of 1999. The subjects' relative finger lengths were recorded on a portable copy machine. The participants also answered a questionnaire about their birth order and sexual orientation. Homosexual women, on average, had a more masculine finger length pattern -- an index finger considerably shorter than the ring finger on the right hand. In men, in general, finger-length ratio did not correlate with sexual orientation. However, some gay men had a greater than usual difference between the lengths of their index and ring fingers, an indication that they were exposed to greater than normal levels of fetal androgens, said Breedlove, who studies the biology of sexual orientation. Previous research by at least one other researcher has found that the more older brothers a boy has, the likelier he is to be gay in adulthood. The Breedlove study confirmed this finding; the gay men had a ratio of 140 brothers to 100 sisters among their older siblings, compared with the general population's ratio of 106 brothers to 100 sisters. The UC Berkeley study also found that men with older brothers had a more exaggerated masculine finger-length pattern than men without older brothers. The number of older sisters was unrelated to finger measures in either men or women. Each subsequent son that a woman has is exposed to higher levels of male hormones, Breedlove said. Even though most later-born sons are heterosexual, the increased androgen level slightly increases the probability of a male child developing a homosexual orientation. "This means that somehow the mother's body remembers how many sons she has had and exposes each successive male fetus to more androgen." Breedlove cautions that these findings are statistical relationships, which say nothing about a given individual. "This is not a test to be used on your friends and neighbors," he said.

-- Poster Guy (posterguy@free.clinic), March 30, 2000

Answers

In a related study, it was found that nosepicking was positively correlated with length of index finger.

-- (nemesis@awol.com), March 30, 2000.

Sorry about shouting the title! I just copied it and didn't think about it being capitalized until after I had pressed submit.

-- Poster Guy (posterguy@free.clinic), March 30, 2000.

Interesting. Especially the bit about the number of older brothers for male homosexuals.

For most of human evolution, we lived in small, isolated bands. The number of available sexual partners was highly limited. The presence of a large number of unattached males in a band would have been bad for social cohesion.

Although this is just a guess, increasing the probablity of homosexuality in later-born sons may have been a way of reducing the risk of internecine conflict, while still retaining the younger males and their adult productive capacity.

The alternatives would be:

- Find mates for them all. This alternative diminishes in prospects as the number unattached males you must provide for increases.

- Let the young men detach from the band. This alternative throws away a lot of effort spent raising them. Lone humans do not survive well, either.

- Let them fight it out with their older brothers for dominance of the few available mates. Ummm -- not a happy outcome. Brothers are genetically similar, so there isn't a lot of gain for later generations by having them compete at producing offspring. Solitary animals might do it this way, but for a social animal this is not a good solution. Cooperation is much better. So, why not tone down the sexual drive in later male siblings, or redirect it?

So, this finding makes pretty good sense to me, when I look at it from a biological point of view.

-- Brian McLaughlin (brianm@ims.com), March 30, 2000.

And we are all now looking at out fingers ...whew, normal =)

-- cin (cinlooo@aol.corn), March 30, 2000.

our*

-- cin (cinlooo@aol.corn), March 30, 2000.

cin -

Very Freudian. It appears that one's fingers can indeed "out" one. LOL!

-- DeeEmBee (macbeth1@pacbell.net), March 30, 2000.

LOLOL Holy shite, I THINK I'm straight! =o)

-- cin (cinlooo@aol.corn), March 30, 2000.

more politically correct junk science sponsored for an agenda, possibly?

-- tt (cuddluppy@aol.com), March 30, 2000.

Brian,

Your theory makes the most sense to me. Having lived and worked in San Francisco, I have known and observed a fair number of gay men, and some gay women. The males that I knew well enough to eventually discuss homosexuality with, almost all indicated that they knew they were different from a very early age. Some of them also expressed that they were also attracted to women, but that the attraction of males was stronger.

-- Flash (flash@flash.hq), March 30, 2000.

Presumably, there should also be a correlation between the survival of older brothers and the eventual emergence of homosexuality in younger brothers. This isn't exactly something "the body remembers" as the researcher hypothesized.

Also, on a lighter note, what does this say about the seventh son of a seventh son?

-- Brian McLaughlin (brianm@ims.com), March 30, 2000.

more politically correct junk science sponsored for an agenda, possibly?

-- tt (cuddluppy@aol.com), March 30, 2000.

Does not fit your preconcieved notions, hence, junk science.

-- Uncle Deedah (unkeed@yahoo.com), March 31, 2000.

So what does this mean for me, since my fingers and toes are all the same size?

-- Finger Question (monkey@boy.ape), March 31, 2000.

Well, if Iunderstand the legends, that indicates that you're a werewolf.

"There, wolf!"

"What?"

"There, wolf! There, castle!"

"Why are you talking like that?"

"I thought you wanted to."

"No. No, I don't."

"Oh, all right then, suit y'self. I'm easy."

-- DeeEmBee (macbeth1@pacbell.net), March 31, 2000.