VICTORIA -- Discrimination and prejudice are inherent genetically encoded biases already in place in the brain circuitry of young infants, researchers claim. Psychologists conclude intolerance of societal heterogeneity is an innate element of the human mindset, starting virtually at birth.

"A central feature of human psychology is our pervasive tendency to divide the social world into 'us' and 'them,' " explained Neha Mahajan of Temple University and Karen Wynn of Yale University. "There is a phenomenon of in-group bias and enhanced interpersonal attraction toward those who resemble ourselves."

The result is ethnocentrism.

"Ethnocentrism is the tendency to view one's group as centrally important," explained Carsten de Dreu at the University of Amsterdam. "It creates inter-group bias."

According to neuropsychologist Allen Edel at the University of Rochester, ethnocentrism is "hard-wired into our brains."

"All successful human societies have a history of excluding out-group members," he wrote.

Paul Bloom at Yale University has concluded that is likely why human infants discriminate against others who are "even slightly different from themselves."

The morality of babies "is focused on people who are similar to them," he added. "The extent to which babies are little bigots, and racism a central part of humanity, (is central to measures aimed) at eradicating racism."

According to the Neonatal Behavioural Assessment Scale, babies only a few hours of age can make judgments on some moral issues.

"Adults tend to like individuals who are similar to themselves," explained University of British Columbia neuropsychologist J. Kiley Hamlin. "Infants and young children prefer individuals who share their attributes and tastes over those who do not."

Hamlin's recent research disclosed that nine- to 14-month-old infants prefer individuals "who treat similar others well."

But, they also prefer those who "treat dissimilar others poorly," she reported.

Her studies indicate the tendency to treat out-group members badly increases with age, and that the anti-outgroup prejudices in the infants she studied were virtually without exception.

De Dreu and colleagues explained there is a hormonal basis to such behaviours.

"Oxytocin creates inter-group bias because it motivates in-group favouritism," the researchers reported. "It strengthens an evolutionary-evolved and functional tendency to discriminate between in-group and out-group (and to give preferential treatment) to members of one's own group."

Some social scientists have expressed shock with regard to such biases being present in young infants.

"In-group cohesion is regulated by oxytocin produced by the hypothalamus," Edel explained. "It is produced (when one encounters) one of one's own kind."

But, when one encounters "a foreigner or a member of some out-group," norepinephrine is produced, and it triggers a fight-or-flight response.

Researchers postulate ethnocentrism has had survival value in human societies because, throughout history, people who were suspicious of members of out-groups "were more likely to survive."

Since bigotry and intolerance are cognitively preprogrammed into the human psyche, addressing these tendencies poses special challenges, psychologists admit. But, in enlightened societies, the "neuroplasticity of the brain" can accomplish amazing feats, according to neuroscientist Sandra Chapman of the University of Texas, although it is not clear if that includes reprogramming itself.

Robert Alison is zoologist and freelance writer based in Victoria.