The most empirically provable (and socaily dismissed) explanation for the evil that man perpetrates on himself has been expressed in God's Word for centuries.
"The heart is more deceitful than all else And is desperately sick; Who can understand it?
Mark 7: 21-23
"For from within, out of the heart of men, proceed the evil thoughts, fornications, thefts, murders, adulteries, 22 "deeds of coveting and wickedness, as well as deceit, sensuality, envy, slander, pride and foolishness. 23“All these evil things proceed from within and defile the man.”