Gareth Cook wrote in the Boston Globe:
"To the litany of arguments against prejudice, scientists are now adding a new one: Racism can make you stupid.
"That is the message of an unusual and striking new series of experiments conducted at Dartmouth College, with the help of brain-imaging equipment and a crew of undergraduate volunteers.
"According to the findings, the more biased people are, the more their brain power is taxed by contact with someone of another race, as they struggle not to say or do anything offensive.
"The effect is so strong, the team found, that even a five-minute conversation with a black person left some of the white subjects unable to perform well on a test of cognitive ability.
“'Just having a prejudice makes you stupider,' said John Gabrieli, a professor of psychology at Stanford University who was not involved in the research. 'It is really interesting.'”