Anthropologists and geneticists have long argued that the concept of
"race" is a misleading way of dividing people into rigid groups that makes
no sense from any scientific standpoint.
Today's study, appearing in the Proceedings of the National Academy of
Sciences, offers fresh evidence to bolster the idea that race is not
"hard- wired" into the brain.
The researchers, from the Center for Evolutionary Psychology at the
University of California at Santa Barbara, concluded that categorizing
people by race was just "a reversible byproduct of cognitive machinery"
that evolved to detect social coalitions.
"Our brains are not designed to make us racists," said senior author
Leda Cosmides. "Our minds are designed to pick up patterns of shifting
alliances of cooperation and competition."
Just how easily the patterns can shift was illustrated in the aftermath
of Sept. 11, she added. The terrorist attacks instantly forged interracial
patriotic alliances, while many of those perceived of Middle Eastern
origin came under heightened suspicion, if not overt hostility, she noted.
Cosmides and her collaborators, Robert Kurzban and John Tooby, ran 52
college undergraduates through a series of laboratory experiments, showing
them photographs of "Euro Americans" and "African Americans" wearing plain
The color of the jerseys was altered by computer, with shirt color used
to delineate shifting teams of players varied to be all of one race or of
mixed race. A series of negative or positive statements was read about
The test subjects were white, including Hispanics, and Asian Americans.
Just how strongly they were unconsciously encoding for race was tested
indirectly by a standard method known as memory confusion, in which errors
of recall revealed how they were categorizing the faces shown in the
There were definite biases against the African Americans at the start,
but the researchers found it took only about four minutes of exposure to
"an alternative social world" to extinguish the racial encoding in favor
of the new marker -- shirt color.
The authors concluded that race was not a fixture in the human mind but
instead a type of "coalition cue" that could be "easily overwritten by new
In real life, racial encoding endures because people think they observe
"patterns of cooperation and competition that correlate with race,"
Cosmides said, even though the evidence is often not closely examined and
may be distorted greatly by social factors.
Evolutionary selection might well have favored hunter-gatherers with
the capacity to tell quickly which strangers they encountered were likely
to be enemies and which might be friends. Yet there is no reason to
suspect that "race" ever mattered in shaping the brain circuitry of modern
humans, Cosmides said, because skin color and other racial markers would
have varied only subtly, if at all, over the limited geographic range of
Other experts said the new findings generally squared with a large body
of evidence, emerging from many disciplines, suggesting that the idea of
race had little meaning other than as a proxy for something else.
"We are not an inherently racist species," said Don Brenneis, an
anthropologist at the University of California at Santa Cruz who is
incoming president of the American Anthropological Association. "But we
are living at a particular historical moment given to a lot of racial
Allen Hart, a social psychologist at Amherst College, was part of a
research team that previously found peculiar patterns of nerve firing in
the brain associated with the perception of race.
But those studies only point to an innate neural network for picking up
any "interesting new stimulus," Hart said, leaving it to some other part
of the brain to figure out whether it's something positive or negative.
This article appeared on page A - 2 of the
San Francisco Chronicle