My conjecture is that for evolutionary reasons, this feature was embedded in the DNA, just as fear of change was, but for different reasons that were exploited to create slaves. The F.O.N.C.'s (Fear Of No Changers) acted as liberators for other F.O.N.C.'s, while the F.O.C.'s (Fear Of Change) people kept to themselves, preferring the soothing regularity that constant routine affords.