On this topic, definitely check out the fascinating work of Michel Tomasello[1]. He's the foremost developmental and comparative psychologist. As I expected,

On this topic, definitely check out the fascinating work of Michel Tomasello[1]. He's the foremost developmental and comparative psychologist. As I expected, his work is copiously cited in the papers[2][3] in the article. Tomasello did studies for over 25 years with human children and other primates on understanding what separates humans from the great apes ("joint agency" and "shared intentionality") and many other topics on developmental psychology. • • • In his recent book, "Becoming Human"[4], he summarizes his decades of research and proposes: ... a new framework for psychological growth between birth and seven years of age. He identifies eight pathways that starkly differentiate humans from their closest primate relatives: social cognition, communication, cultural learning, cooperative thinking, collaboration, prosociality, social norms, and moral identity. In each of these, great apes possess rudimentary abilities. But then, Tomasello argues, the maturation of humans’ evolved capacities for shared intentionality transform these abilities—through the new forms of sociocultural interaction they enable—into uniquely human cognition and sociality. The first step occurs around nine months, with the emergence of joint intentionality, exercised mostly with caregiving adults. The second step occurs around three years, with the emergence of collective intentionality involving both authoritative adults, who convey cultural knowledge, and coequal peers, who elicit collaboration and communication. Finally, by age six or seven, children become responsible for self-regulating their beliefs and actions so that they comport with cultural norms. [1] https://en.wikipedia.org/wiki/Michael_Tomasello https://en.wikipedia.org/wiki/Michael_Tomasello [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6389704/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6389704/ [3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461303/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461303/ [4] https://www.hup.harvard.edu/catalog.php?isbn=9780674248281 https://www.hup.harvard.edu/catalog.php?isbn=9780674248281