Humans have a powerful instinct for forming into tight-knit groups,
be they tribes, sports clubs, countries or political parties. This makes
sense – we can achieve more together than alone, and no doubt
those of our ancestors who were motivated to form such groups
were more successful and more likely to procreate than those who
operated individually. Moreover, an inbuilt inclination to in-group
loyalty and bias can help foster cooperation and improve group
effectiveness. But there is a serious downside to this behaviour. The
demon twin of in-group loyalty is out-group prejudice. With such
powerful impulses, it’s no wonder that human history is pockmarked
by deadly wars and skirmishes, with one gang, tribe or country
facing off against another.
A classic study from the 1970s by the British psychologist Henri Tajfel
showed just how arbitrary in-group loyalty can be. Tajfel and his
colleagues divided schoolboys from Bristol into two arbitrary groups
based on their stated preference for the abstract art of either Klee or
Kandinsky. Next, the boys were asked to make a series of decisions with
regards to allocating money between pairs of their peers. Crucially, the
identity of these peers was hidden except for their group membership.
The boys showed some effort at distributing the money fairly, but they
couldn’t help themselves from consistently allocating more money to
other boys who were in their recently created group.
Racial prejudice
One of the banes of modern life and one of the most divisive expres-
sions of in-group bias is racism – people making assumptions about
another person on the basis of his or her apparent racial background.
Plenty of research shows that this tendency to categorize and judge
people by outward racial appearance begins from an early age. Four-year-