by Nicholas Katz
Handedness is an attribute of human beings defined by their unequal distribution of fine motor skill between the left and right hands. An individual who is more dexterous with the right hand is called right-handed (RH); all others are called non-right-handers (NRH) when studied scientifically. About 91% of the population are right-handers, the rest are non-right-handers. Most people assume that there is no single ‘handedness’ gene because it is not simply inherited. Two left-handed parents, for example, will often have right-handed children. Dr. Amar Klar, a researcher at the National Cancer Institute came up with a new theory that seems to explain how this is possible. The basics of which are described here.
Suppose there is a single gene that controls handedness, called RGHT. If you have a RR or Rr, you are RH. If being a NRH is a recessive gene, then all NRH would have to be rr. Thus, all the children of two NRH would have to be NRH. Klar explains this by suggesting what he calls a “random recessive” gene. This means that those who have the rr gene have a 50% chance of being either RH or NRH. Thus of the population, the 91% RH are either RR, Rr, or rr, and the 9% NRH are all rr. More on the genetics can be found here. Klar also related this to hair whorls, which is the direction the hair on the top of your head spins. 91% of the population had clockwise hair whorls, while 9% have counter clockwise hair whorls. Thus, the majority of the population is right handed and has a clockwise hair whorls. Those who are NRH have a 50/50 shot of having a clockwise or counterclockwise whorl. This led Klar to hypothesize that the genetics of hair whorls and handedness are related. Klar’s full article can be found here. Klar also investigated the link between homosexuality and hair whorls, and found that homosexual men have increased rates of counterclockwise hair whorls. This study can be found here.
When I saw this article, the first thing I thought of was another article I read over the summer in New York magazine. It’s called “The Science of Gaydar.” The article was really interesting, addressing the link between handedness, hair whorls, and homosexuality, but it also looked at other connections, adding a new level to the science of homosexuality.
“Gaydar,” for anyone that doesn’t know, refers to the ability to identify an individual, based on appearance and/or actions, as a homosexual. Other than hair direction and hand preference, finger lengths have been correlated to being gay. Men usually have a shorter index finger than ring finger, while women tend to be closer to equal, sometimes even reversing the relationship. Gay men generally mimic women’s fingers and gay women have relative lengths that follow the pattern of straight men.
But do people really scan crowds in search of finger lengths? Probably not, but it may be something we subconsciously identify as “masculine” or “feminine.” More striking was a study mentioned in the article that had participants identify voices as gay or straight. 75% of gay male voices were correctly categorized. Does this mean there is a “gay accent?” Who knows, but the connections are very interesting!
The whole article is long but for more information, here’s the link:
http://nymag.com/news/features/33520/
Comment by Dorie Obertello — February 18, 2008 @ 10:01 pm
Although the studies about the correlation between homosexuality and left handedness is very interesting, I think it is important to look at the issues that studies like this raise. For instance, neuropsychologist Simon Le Vay points out that “The data obscures the fast that most homosexuals are right-handed, and most left-handed people are heterosexual” (Quoted by Bode, 2000). He is making the point that, although the data raises some interesting point about the possible relationship between sexual orientation and traits, it is important to not use it to make generalizations about people with those traits.
Reference:
Bode, N. (2000, Nov/Dec). Sexuality at Hand. [Electronic version]Psychology Today Magazine. (Retrieved March 29, 2008 from http://psychologytoday.com/articles/pto-20001101-000005.html)
Comment by Beryl Gilothwest — March 29, 2008 @ 9:06 am
[...] often have … Klar also related this to hair whorls, which is the direction the hair on the top …http://intro2psych.wordpress.com/2007/12/26/handedness-hair-whorls-and-homosexuality/This my LandCrazy John, the lazy bastard, was no respecter of the dead or the living either, for [...]
Pingback by whorls going to the left — July 24, 2008 @ 5:53 am
[...] Handedness, hair whorls, and homosexuality [...]
Pingback by Homosexuality, evolutionary psychology and cognition | Encefalus — July 31, 2008 @ 6:29 pm
This research is interesting, but on the other side, it may be completely irrelevant to the subject and may be due to error on the researcher’s part. If you wish, check out my thoughts on homosexuality at http://encefalus.com/cognitive/homosexuality/
Comment by Encefalus — July 31, 2008 @ 6:30 pm