Study Links Genetics, Male Homosexuality : Research: Canadian scientists say gay men have more ridges in fingerprints. It bolsters the theory that sexual orientation is determined before birth.
WASHINGTON — Two Canadian researchers have found a link between the number of ridges in fingerprints and male homosexuality, adding to the theory that sexual orientation is determined before birth.
The researchers, working at the University of Western Ontario, compared the number of tiny ridges on the fingertips of 66 homosexual men with the fingerprint patterns of 182 heterosexual men.
About 30% of the gay men showed more ridges on their left hands than their right, while only 14% of the heterosexual men showed the same pattern.
Most men and women have more ridges in the fingerprints of their right hands. Fingerprints are completely developed in human fetuses by about the 16th week after conception and are largely genetically determined.
“This certainly suggests sexual orientation is somehow determined by prenatal events,†said researcher Doreen Kimura.
The study appears in the December issue of Behavioral Neuroscience.
“What we found is a statistically significant difference between groups of heterosexual and homosexual men,†Kimura said.
Roger Gorski, a UCLA neurobiologist who has done extensive research on sexual differentiation, called the study “another suggestion that there’s a biological component to sexuality.†But he said he had some trouble with making the connection between ridges on fingers and sexual orientation.
