A controversial study by American researchers reveals that racism is "hardwired" in the brain and even right thinking people may unconsciously harbor a negative attitude towards specific races.
The same circuit in the brain that allows people to see which ethnic group a person belongs to overlap with others that drive emotional decisions.
As a result even right-thinking individuals make unconscious decisions based on a person's race.
Brain scans have proved that interactions with people of other ethnic backgrounds set off reactions that may be completely unknown to our conscious selves.
The findings may force researchers to think about racism in entirely new ways.
It's possible, the researchers say, that even right-thinking, 'egalitarian' people could harbour racist attitudes unknowingly.
According to the new research, the chemicals involved in perceiving ethnic backgrounds overlap with those for processing emotion and making decisions, according to new research.
And the findings could lead to fresh ways of thinking about unintended race-based attitudes and decisions.
Dr Elizabeth Phelps, of New York University, and colleagues reviewed previous brain scanning studies showing how social categories of race are processed, evaluated and incorporated in decision-making.
They showed a network of brain regions called the amygdala, dorsolateral prefrontal cortex and the anterior cingulate cortex are important in the unintentional, implicit expression of racial attitudes.
The researchers said the brain areas themselves - as well as the functional connectivity among them - are critical for this processing.
"A few decades ago, it was unthinkable that looking at the brain to understand representations of social groups such as black versus white was even possible, let alone that such explorations could yield useful knowledge," the Daily Mail quoted Dr Phelps as saying.
"Evidence from neuroscience has been vital in clarifying the nature of how intergroup cognition unfolds.
"Moreover, the neuroscience of race has been useful in pointing the way toward the type of new behavioural evidence needed to answer questions of not only what happens when intergroup cognition is at stake, but whether and how change is possible in real human interactions," he added.
The findings were published in Nature Neuroscience.