Is Aristotle's theory of race correct?

This is a philosophy thread, dumb mods.
Is there a good argument against the obvious pragmatic value of racism? It improves in-group cohesion, fosters ethnically-inclined values and traditions, which leads to general improvement of the population through shared experience. A cohesive group is bound to outperform an atomized group.
Antiracism or "individualism", as far as I can see, only offers one trade-off benefit of enabling the individualist to 'see past race', an ability which offers marginal benefits in things like employment and socialization.