This paper argues that to explain the institutionalization processes named the family and marriage, it is necessary to recognize the ontological distinction between their cognitive and relational realities. Institutionalization is an ordering process analogous to instinct in animal societies. In that capacity the human family and marriage collectively order the care and social placement of offspring. Given the biology of Homo sapiens, the family preceded the onset of the human race by millions of years, whereas marriage, the contract that legitimates the social placement of offspring, represents a strictly cultural aspect of human social evolution. The current state and uncertain future of the cognitive and relational components of the institutions of the family and marriage are addressed.