Evolutionary Adaptedness (EEA)
The environment of evolutionary adaptedness (EEA) is a concept developed by John Bowlby in regards to his attachment theory. It describes the conditions and properties of the external world in which evolutionary adaptations occur. It is not a specific place but a conceptual environment.
Two different organisms in the same physical environment (a fox and a butterfly) may have the same shared forest setting as their ancestors but have differing EEAs. Their ancestors faced different conditions, reproductive challenges, and social conditions making their EEA unique to their species.
Bowlby used EEA to describe the situational and external factors in which an evolved trait adapted from over time. The EEA is the collective influence of selection that caused an adaptation to develop. The EEA of early humans that resulted in our brain development is very different than the environment we face in modern society. Our brains evolved in early hunter-gatherer and nomadic societies which differ greatly from the majority of the modern human population. Some psychologists argue that modern society is 'mismatched' with the human EEA. Our culture is not set up in a way that is conducive to how environmental conditions were when our brains evolved.