Chapter 2 addresses the question of what develops; the main argument of ECT is that most talent domains as defined by culture are not genetically programmed or preordained; however, most human accomplishments or excellence we know of are traceable to our ancient, even prehistorical roots when Homo sapiens still lived a hunting-and-gathering life. Therefore, any talent we are familiar with can be seen as a new machine made of “old parts” ever-present in prehistorical times and everyday life, a set of bioecological effectivities that have a long history of serving the surviving-thriving function in human ecology, only gradually to be harnessed and further refined through enculturation and institutionalized education and training, supported by cultural niche construction and infrastructure. Here lies a critical distinction between typical development in an expectant cultural environment and optimal development in a highly enriched one, potentially resulting in social disparities. Along the way, evidence of developmental diversity and divergent pathways suggests spontaneous self-organization of bioecological aptitudes and dispositions in adapting to affordances and challenges presented in a sociocultural environment, laying the foundation the growing person–object or person–world relationships.