An Eye for Sexual Orientation

By Matt Kaplan
ScienceNOW Daily News
18 January 2008Talk about "gaydar." In just a fraction of a second, people can accurately judge the sexual orientation of other individuals by glancing at their faces, according to new research. The finding builds on the growing theory that the subconscious mind detects and probably guides much more of human behavior than is realized.

Humans are remarkably good at making snap judgments about others. In a hallmark study conducted by psychologists Nalini Ambady and Robert Rosenthal in 1994, people shown 2-second video clips of professors teaching formed opinions about the professors' teaching abilities that were uncannily similar to evaluations written by students at the end of a semester. The results led psychologists to begin questioning what else people might detect in a glance.

Ambady and colleague Nicholas Rule, both at Tufts University in Medford, Massachusetts, wondered about sexual orientation. They showed men and women photos of 90 faces belonging to homosexual men and heterosexual men for intervals ranging from 33 milliseconds to 10 seconds. When given 100 milliseconds or more to view a face, participants correctly identified sexual orientation nearly 70% of the time. Volunteers were less accurate at shorter durations, and their accuracy did not get better at durations beyond 100 milliseconds, the team reports in an upcoming issue of the Journal of Experimental Social Psychology. "What is most interesting is that increased exposure time did not improve the results," says Ambady.

Romantic attraction likely works just as fast, notes psychologist Paul Eastwick of Northwestern University in Evanston, Illinois. "If people make accurate judgments about sexually relevant aspects of a person this quickly," he says, "you have to stop and wonder how we size up one another's romantic potential in a matter of milliseconds."

Psychologist David Kenny of the University of Connecticut, Storrs, says the finding demonstrates the brain's remarkable ability to make fast yet accurate appraisals. Still, he notes that with some of the images, accuracy regularly fell below 50%. It's possible that some faces are just hard to read.