Introspection can cause insanity.. Though Reb Nachman's idea of hisbodadut and speaking with God from one's heat in one's mother tongue is a great idea but it can be overdone and lead to insanity as we can in fact. The point here is it is possible and desirable to generalize about groups.There is such a thing as a Bell Curve and average behavior. If a group on the average displays a high degree of mental instability then it is permissible and desirable to generalize about it and ponder what is the cause?