 A fairly uncontroversial background tenet of the received view is that humans are extraordinarily social animals, and that our hypertrophied abilities to learn from and cooperate with each other are key to what set us apart from our closest primate ancestors and other hominid species. A crucial difference is thought to be that human capacities to imitate and learn from each other became powerful enough to sustain cumulative culture (Tomasello 1999; J. Henrich &amp; McElreath 2003, Laland 2017). Culture is understood as information that is transmitted between individuals and groups via behavior, rather than processes like genetic transmission (Ramsey 2013). Beliefs, preferences, norms, skills, techniques, information-containing artifacts, etc., are passed from individual to individual, and thus across populations and between generations, mainly by social learning (Mathew &amp; Perreault 2015). For example, development of the set of techniques and skills associated with throwing spears, or the knowledge and tools enabling the controlled use of fire, have been tied to increases in opportunities for social learning provided by expanding social networks and more complex forms of social activity (Thieme 1997; Gowlett 2006). Culture is cumulative in the sense that the body of information in the cultural repository does not remain static, but can itself grow larger and more complex. Grass huts evolve into wood-frame houses, then brick buildings, and eventually skyscrapers. Tribal leaders evolve into kings, then emperors, then prime ministers. Simple sets of norms evolve into more complicated informal institutions, then byzantine formalized legal codes. As each generation adds its own new innovations, discoveries, and improvements, functional sophistication is accumulated in cultural traits in much the same way as it is accumulated in genetic traits.