The years since the publication of Machiavellian Intelligence have witnessed a golden age in discoveries concerning social cognition in human and nonhuman primates and many other animal taxa too. Here, I briefly dissect some of the variants of the social intelligence hypotheses that have evolved in this time and offer a selective overview of the scientific discoveries in this field, particularly in primates, over the last 30 years. (PsycINFO Database Record (c) 2018 APA, all rights reserved)