Long before they are able to talk, walk, or even sit up, babies are able to distinguish among different races and genders. A psychologist from the University of Delaware has found that babies are able to classify people by race and gender at 3 months; by 9 months, babies have difficulty remembering the faces of people from less-familiar races.

At 3 months, Paul Quinn says that Caucasian infants prefer Caucasian faces over Asian faces, choosing to stare at Caucasian faces for longer periods of time. At 3 months, infants were able to remember faces of different races equally, but that ability disappeared by the time babies were 9 months old.

Researchers measured babies' preferences by noting how long they stare at different objects, since babies of those ages are generally unable to speak. Looking time also demonstrates babies' familiarity with objects. Babies look at things for longer periods of time when they are more unfamiliar with it; when babies see familiar objects, they spend less time looking at them.

Researchers showed infants pictures of people of the four major ethnic groups: African, Caucasian, East Asian, and South Asian. They realized that 3-month-olds were able to recognize faces from all races, not just their own, but that the ability disappeared for 9-month-olds. Researchers wondered if that development could be changed.

They asked parents of 6-month-olds to read to their children using picture books. These books featured pictures of people of different races. After showing them the books, the Caucasian babies, at 9 months old, would be able to differentiate between Asian faces as they had been able to do when they were younger.

A similar study showed daily videos of Asian faces to 8-month-old Caucasian babies. After two to three weeks, Quinn said that he and his team "were able to reverse the way their perception [otherwise] narrowed."

The study aligns with a famous tenet of psychology called the cross-race effect. It stipulates that people tend to have greater difficulty remembering the faces of people of different races than their own.

A study published earlier this year found that racism is hardwired into people's brains. According to the study published in Nature Neuroscience, researchers found that the brain circuits that allow people to classify others into ethnic groups and the circuits that process emotion and make decisions overlap. They said that it was that circuitry that allowed people to make unconscious decisions based on race, and is responsible for many of the race-based stereotypes that people make.

Quinn's research team also found that babies preferred female faces, but they realized that the preference existed in babies with female primary caregivers. In babies whose primary caregivers were men, they preferred men.

It is possible that this distinction that babies make between races and gender has evolutionary roots. In ancient times, people needed to distinguish early on among people of different tribes.

Quinn's studies also cast light on the question of whether racism and sexism can be reversed.