A term devised by John Bowlby (1907-1990) in the context of the Bowlby-Ainsworth theory of attachment to denote the environment to which a species has become adapted during its phylogenetic history such that, for example, a system of maternal behavior co-evolved with a complimentary system of infant attachment behaviors, thus ensuring protection for young organism in particular and for the species in general. In the human environment of evolutionary adaptedness, maternal behavior involves continuous carrying of the pre-walking infant and breast-feeding on demand, and for the infant it consists of variations in cry vocalisations and a complex suite of feeding behaviors such as the rooting response and the burst-pause pattern of nutritional sucking on the breast. In essence, the environment of evolutionary adaptedness for the human newborn and young infant is living on the body of the mother in that neonatal behavior represents an elegant adaptation to this particular ecological niche. With the widespread change from a hunter-gatherer to a settled agrarian existence some 10,000 years ago, the environment for the infant was changed to one consisting of discontinuous carrying and feeding on schedule. Given the short span of time in evolutionary terms, it is unclear if this change has had detrimental influences for child development. Certainly, the move away from breast-to bottle-feeding in recent years has led to a greater incidence of childhood infections in developing countries, with associated increases in the rates of morbidity and mortality in such countries. Bowlby (1969) indicated that his notion of the environment of evolutionary adaptedness was a version of ‘man’s ordinary expectable environment’, put forward by the ego psychologist Heinz Hartmann (1894-1970) in 1938.
See Adaptation, Attachment theory, Co-evolution, Environment, Evolutionary psychology, Newborn, Niche (ecology), Proximal care