quality:correction, structural:reformatting
Environment of evolutionary adaptedness

The environment of evolutionary adaptedness is significantly different from modern society. The ancestors of modern humans lived in smaller groups, had more cohesive cultures, and had more stable and rich contexts for identity and meaning. Researchers look to existing hunter-gatherer societies for clues as to how hunter-gatherers lived in the environment of evolutionary adaptedness. Unfortunately, the few surviving hunter-gatherer societies are different from each other, and they have been pushed out of the best land and into harsh environments, so it is not clear how closely they reflect ancestral culture. However, all around the world small-band hunter-gatherers offer a similar developmental system for the young ("hunter-gatherer childhood model," Konner, 2005; "evolved developmental niche" or "evolved nest;" Narvaez et al., 2013). The characteristics of the niche are largely the same as for social mammals, who evolved over 30 million years ago: soothing perinatal experience, several years of on-request breastfeeding, nearly constant affection or physical proximity, responsiveness to need (mitigating offspring distress), self-directed play, and for humans, multiple responsive caregivers. Initial studies show the importance of these components in early life for positive child outcomes.