What does that mean? What does it mean to say that a baby is psychologically effeminate? It seems to me that people learn how to behave and think. There is no such thing as an innate psychology. I think you are mistaking cultural behavior as some how biologically hardwired rather than learned.
For example i would not think that a girl was acting like a boy if she chose to play with an action man rather than a Barbie doll. That people would think that this was odd behavior is due to how a group people culturally and subjectively choose to express their sexuality, and has nothing to do with how they are born.
“Early sex hormones have an organizing effect on the brain that’s permanent,” Manning says. But the differences between the sexes aren’t all that interesting to biologists. More telling are the variations within each sex.** Females with masculine digit ratios have more masculine behaviors, he says. Likewise, males with a typically female ratio exhibit more typically feminine behaviors.**
A study of digit ratio in Scottish preschool children between the ages of 2 and 4 found strong relationships between digit ratio and gender-normative behavior. Girls with masculine-type finger ratios tend to have higher hyperactivity scores and more problems relating to their peers than do other girls. The same study, published in
Early Human Development, found that boys with female-type finger lengths are on average more emotional than other boys. “They tended to be very sensitive,” says Manning.
Except for genitalia, relative finger length is the only physical
trait fixed at birth that is sexually dimorphic—meaning males and females show typical
gender differences. Other sexually dimorphic traits, such as height and waist-to-hip ratio, don’t appear until
puberty.
“Everything you see as far as sex differences in the behavior of toddlers is an aftereffect of prenatal testosterone,” says Dennis McFadden, a psychology professor at the University of Texas at Austin. Manning and others have linked finger length ratios to aggression, left-handedness, heart disease,
autism and
attention deficit disorder, all traits that are more common in men. (Studies indicate they are most common in men with longer than average ring fingers.) A “masculine” finger pattern seems to similarly mark girls predisposed to hyperactivity and autism.
Some scientists believe prenatal sex hormones are also part of the puzzle of
homosexuality and that a high level of testosterone may wire the brain for attraction to the same sex. Intriguingly, research shows that a prenatal testosterone level is most strongly linked to homosexuality in women, according to an article in the
Archives of Sexual Behavior.
Lesbians are more likely than straight women to have a masculine finger ratio, says McFadden.
The data in men, however, are more complicated and contradictory. Some studies have shown hypermasculine finger length in gay men, while other studies show the opposite, a female-like finger pattern. The picture is further muddied by geography. Race and ethnic differences seem to affect digit ratio, although scientists don’t yet understand how.
Still, even if prenatal testosterone is a factor in homosexuality, it’s unlikely to be the only element. Studies indicate
genes wield much influence.
Even as digit ratio research flourishes and more behavioral links are established, the relationships will remain mere statistical correlations until researchers fully understand how sex hormones physically affect the brain. The reigning hypothesis is that testosterone encourages growth in the right side of the brain, while inhibiting growth in the left. Animal models using rats, mice and sheep show that testosterone boosts growth in a part of the hypothalamus involved in sexual behavior and fertility.
In sheep, males with hypermasculinized brains are sexually attracted to other males."
psychologytoday.com/articles/200506/sexuality-your-telltale-fingertips
