That information, proponents say, can be fed into machines capable of detecting the most minute patterns, and pick up on physical differences that a human observer could never see.
It sounds fascinating, but to many critics, this is just plain old bad science hiding beneath the veneer of mathematics—algorithms instead of men with calipers measuring noses and brows. And they cite an endless parade of concerns about ethics, privacy, and the introduction of numerous potential biases, intentional or not, into the algorithms that might one day, with a single scan, determine our fates.
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While few scientists dispute that physical characteristics can sometimes reveal something about the internal hard-wiring of a person—the testosterone-face connection, for example—the inferences that can be drawn from such observations are vanishingly small. Lisa DeBruine, who coheads the Face Research Lab at the University of Glasgow’s Institute of Neuroscience and Psychology, describes herself as an evolutionary psychologist, but she is not shy about the shortcomings in the field. As for width-to-height ratios, “that area of research is a real mess,” she said, largely because of inconsistencies in how both humans and computers measure things like the distance from a chin to a brow or cheekbone to cheekbone.
DeBruine was one of many critics of Kosinski’s study, which sought to train a computer to identify who was gay and who was straight, based solely on scans of faces from a dating site, where users clearly identified their sexual orientation or preference. Kosinski claimed that, given two new photos, one of a straight person and one of a gay person, the computer was able to guess with a high degree of accuracy which one was gay. He also tested the algorithm on Facebook photos the computer had never seen, and it seemed to get it right—at least for gay people. The algorithm seemed to do less well identifying straight people.
(This may sound counterintuitive, but the algorithm wasn’t using the process of elimination. Rather, when given the binary choice of identifying a single person in a photograph as being straight or gay, it seemed to get it right less often when presented with a straight person, assigning them as gay when they were not.)
In his paper, Kosinski said the computer was zeroing in on certain physical features of the face consistent with prenatal hormone theory (PHT), which suggests that gay people are so because they were exposed to differing levels of androgens in the womb. “The faces of gay men and lesbians had gender-atypical features,” the scientist wrote, “as predicted by the PHT.” Kosinski argues that prenatal hormone theory is “widely accepted” as a model for the origin of homosexuality.
Critics, though, said there are several problems with Kosinski’s formulation, including a variety of stereotypical assumptions, and a failure to appreciate that PHT isn’t necessarily as solid as it sounds. The computer might also be picking up on something besides a feature set that defines gayness.