Why humans made it, and chimps didn’t

Fascinating work on the comparative cognitive and social behavior of humans and chimpanzees continues to pour out, highlighting behaviors that made us human. Yamamoto et al. show that Chimpanzees can understand conspecifics’ goals and demonstrate cognitively advanced targeted helping as long as they are able to visually evaluate their conspecifics’ predicament. However, they will seldom help others without direct request for help. And, Dean et al. compare higher-level problem solving behaviors in Capuchin Monkeys, Chimpanzees, and human infants, finding that a package of sociocognitive processes are found only in humans:

The remarkable ecological and demographic success of humanity is largely attributed to our capacity for cumulative culture, with knowledge and technology accumulating over time, yet the social and cognitive capabilities that have enabled cumulative culture remain unclear. In a comparative study of sequential problem solving, we provided groups of capuchin monkeys, chimpanzees, and children with an experimental puzzlebox that could be solved in three stages to retrieve rewards of increasing desirability. The success of the children, but not of the chimpanzees or capuchins, in reaching higher-level solutions was strongly associated with a package of sociocognitive processes—including teaching through verbal instruction, imitation, and prosociality—that were observed only in the children and covaried with performance.