&gt; &quot;Humans evolved to be violent and critical, because the tribes that didn&#x27;t have that attribute got killed off, conquered, or died of starvation during hard times.&quot;<p>Why are you so sure that it was competition and not cooperation that ensured the strength of a tribe?<p>Or to put it another way, could cooperation, even cooperation with those you dislike, also lead to a materially successful tribe?