Perception of faces is biased toward the opposite gender after six seconds… (AH Javadi/PLoS ONE )
Repeated exposure to objects like high-heeled shoes and electric razors that are typically associated with one gender or the other biases people's perceptions of whether human faces are male or female, according to a new study. And in a twist, the research shows that exposure to female-associated objects makes faces look more male, and vice versa.
It may seem strange that viewing something for an extended period of time can lead to increased perception of its opposite, but the effect is common enough to have a name: adaptation. It crops up under a variety of circumstances: If you look at a computer screen colored red and it suddenly turns white, you will see green, for example. Similar effects have been seen for an object's shape, or its motion.
But adaptation can also rise above these basic visual features and impact our perception of "high-level" concepts like race and gender: Prolonged exposure to a stereotypically male gait, for example, has been shown to make a subsequent gender-neutral gait look female.
Past studies have focused on objects from the same category. For instance, the way a face looks has been shown to bias perception of later faces. This makes it difficult to rule out that some particular feature -- say, the face’s shape -- is what’s biasing the viewer.
In order to prove that the brain is in fact responding to gender, the researchers who conducted the new study tested the effects of objects of different categories. They asked people to memorize a series of pictures of either female-associated objects like high heels and lipstick or male-associated objects, like loafers and electric razors. Then they asked whether a series of androgynous faces looked male or female.
If the brain was simply responding to low-level visual features like shape, the task should reveal nothing. But if adaptation was occurring in a brain network that encodes for gender, it wouldn’t make much difference whether study subjects were looking at circles or squares—or shoes or razors. All that would matter would be the degree to which the objects are linked to men or women, since the network would only be "listening" to the objects' gender association. In that case, there would be an adaptation effect that would cross over from objects to faces.
And that is what they found: When subjects viewed male-related objects, they were more likely to think a gender-ambiguous face was female. Meanwhile, the subjects who saw female-related objects thought the same faces looked like men.
The study reveals how the objects we interact with every day can subtly impact the way we view the people around us. It also suggests that our brains can be fooled into being less than rational in an uncountable number of ways.
Finally, the results provide some of the best evidence yet that there is a network in the brain whose job is to tell male from female.
You can read the full study here.
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