Evolution of Human Parental Behavior and the Human Family

Abstract

SYNOPSISObjective. To develop an evolutionary model that integrates human parenting and family formation with ideas about the evolved functions of distinctive human characteristics, such as concealed ovulation and sophisticated sociocognitive competencies. Design. Theoretical and empirical research across scientific disciplines is reviewed. The emphasis is on ecological and social conditions that covary, across species, with parenting, family formation, and potentially coevolving characteristics, such as a long developmental period. Results. For humans, social competition through coalition formation emerges as the key selective pressure that readily explains the coevolution of a constellation of characteristics that covary with parenting and family formation, including a lengthy developmental period, reduced sexual dimorphism, concealed ovulation, menopause, complex kinship networks, large brains, and sophisticated sociocognitive competencies. Individual and cross-cultural variations in patterns of parenting dynamics and family formation are viewed as adaptive phenotypic responses to different ecological and historical conditions. Conclusions. Human parenting and family formation are features of a coevolving suite of distinctive human characteristics, the evolutionary function of which is to facilitate the formation of kin-based coalitions for competition with other coalitions for resource control. In this view, a central function of human parenting and the human family is to provide a context for the development of sociocompetitive competencies appropriate to the local ecology.

From Phylogeny to Ontogeny of Longevity: Contributions of the Evolutionary Approach to Gerontology

“…A parallel is found in current pre-industrial societies, where parents usually commit infanticide to reduce the risks for their older children (Daly & Wilson, 1988;Hill & Hurtado, 1996). When this pattern is combined with an increase in the development period, menopause comes as a logic evolutionary adaptation with the same function-reducing the number of dependable children so the parental resources may be applied to a smaller number of children (Geary & Flinn, 2001). Charnov (1993) considers to be likely that during the hominidae evolution the clear increase in lifetime is partially related to this increase in parental investment (all the efforts and expenses associated to the production, gestation, post natal care, food, and protection of the young ones), which, on its turn, becomes reproductive benefits and more favorable life conditions in this stage.…”

Local Scarcity of Women Predicts Higher Fertility among Married Couples and More Single Father Households

“…Women attract partners through signals of fecundity and suggestions of sexual access. Men attract partners through signals of potential commitment to longterm relationships and resource provisioning (Buss & Schmitt, 1993), which is substantially larger in humans than in other primates (Geary & Flinn, 2001).…”

Moral Action as Cheater Suppression in Human Superorganisms

“…Sequestering of newly reproductive females in puberty huts and restriction of their social movement until pair-bonded ensure that exposure to males is minimized early in life. Concealed ovulation ensures that males do not fight over access to a woman during a brief, obvious period of fertility, reducing sexual tensions in a group, and making it possible for some reproductive cycles to pass without insemination, reducing fertility (Geary and Flinn, 2001;Marlowe and Berbesque, 2012). During the majority of a human female's reproductive career, she is (except in extreme ecological circumstances) limited to forming a single breeding pair (i.e., monogamy) (Zeitzen, 2008;Chapais, 2013).…”

“…Nevertheless, there is a strong division in the human superorganism between "somatic" functions and the reproductive function. In particular, a specialized institution, the human family, has evolved as the vehicle for reproduction (Emlen, 1995;Geary and Flinn, 2001), which serves to restrict both genetic variability in human populations (which is very low compared to other primate species) (Bowden et al, 2012), and overall group population size. While human females are born with around two million eggs, a variety of mechanisms have evolved to reduce actual completed fertility to a very small number.…”