Michael Tomasello

Michael Tomasello supplies the “shared-intentionality” account of human ultrasociality that Jonathan Haidt builds on in The Righteous Mind. In the book’s telling, Tomasello argues that human ultrasociality arose in two steps: first, the ability to share intentions within small groups of two or three actively hunting or foraging together (Haidt calls this the Rubicon — “two chimpanzees carrying a log”); then, over hundreds of thousands of years, more collaborative groups grew larger, perhaps in response to the threat of rival groups, with victory going to the most cohesive groups — those that could scale shared intentions from three people to three hundred or three thousand.

Tomasello also reframes language as downstream of this capacity rather than its cause. Many assume language was our Rubicon, but Tomasello holds that language became possible only after shared intentionality: a word is not a relationship between a sound and an object, but an agreement among people who share a joint representation of their world and a set of conventions for communicating about it. Kyle’s notes link this to Sapiens’s narrative-as-glue thesis — the human mind as “a story processor” — making Tomasello’s cooperation argument a complement to the role stories play in binding humans into groups.

Context: Michael Tomasello is a developmental and comparative psychologist (long at the Max Planck Institute for Evolutionary Anthropology, later Duke) known for his research on shared intentionality and the cognitive differences between humans and other great apes, summarized in works like A Natural History of Human Thinking.

Where this appears

• The Righteous Mind — Tomasello’s two-step account of human ultrasociality and his claim that language followed shared intentionality, which Haidt uses to ground his moral-psychology argument.