A classic experiment by Henri Tajfel provides evidence for the conclus
ion that the division of a group into subgroups is enough to trigger d
iscriminatory behavior, even if there is no reason for such behavior i
n terms of the individual's own interest. I don't challenge that concl
usion; but I question an implicit assumption which is suggested by the
experimental setup and by the language used by Tajfel in describing t
he experiment. The assumption is that an initially coherent group will
typically experience division as a result of outside influence. A tot
ally different picture of the situation and totally different social p
olicy recommendations will follow if we believe instead that groups ar
e evolving structures, and specifically structures that constantly and
autonomously come into conflict with themselves.