The critical point of that story was that it was not random which baboon died. The garbage dump area which had the infected food "belonged" to an other baboon s

The critical point of that story was that it was not random which baboon died. The garbage dump area which had the infected food "belonged" to an other baboon squad, so it was only the most aggressive males that dared to invade in order to eat there. Naturally the troop overall got less aggressive when the top 50% most aggressive males died. What was surprising to Sapolsky and scientific notable was that the lower aggression continued even when the troop returned to the original gender composition several years later, including new males which had no genetic relatives with the troop. The theory is that a culture of low aggression was introduced by the eradication of the aggressive males, and new males simply adapted to that culture when they joined.