Typically, the child-rearing not done by parents is done by peers.
Fatherhood, being (unlike biological paternity) a socially-constructed relationship of social identity, provision, care and attention, varies much more across (and within) cultures than does motherhood, which is far more biologically-grounded (at least until the infant is weaned). A small number of societies traditionally did not recognise the relationship of fatherhood at all, the role of male protector being taken by uncles. Even beyond such outliers, evidence from the anthropological literature is that the father’s attention is a highly variable factor in child-rearing.
The investment in attention and feeding required to raise a human child is considerable. Far more than is required to raise the young of any other species. As pregnancy and lactation ties women to the raising of infants, this leads to recurring risk-management patterns across human societies whereby activities that are compatible with breast-feeding, and other aspects of child-minding, become presumptively female roles. Those activities that are not thus compatible become presumptively male roles. The first scholarly explication of this was in a classic short analysis by anthropologist Judith K. Brown. An analysis that subsequently acquired considerable statistical and other support.
In his The Lifeways of Hunter-Gatherers: The Foraging Spectrum, archaeologist Robert L. Kelly includes a very useful summary of the anthropological evidence on child-rearing and its interaction with the acquisition of culture. (All quotes are from Lifeways, mainly Pp108–110.)
The two dominant social sources for transmitting or acquiring culture are parents and peer groups. They generate rather different patterns. Parents, particularly, mothers, are predictable and consistent providers of resources — breast milk, food, affection, attention and protection. Over time, the parents provide less and less resources until eventually the child is cut off.
It has been reasonably argued that parent-raised children learn that “resources and desirable goods are limited and hard to obtain”. They can also be expected to tend to be assertive and independent, focusing on using knowledge of terrain and technology to gain resources rather than social favours. In nomadic societies, boys tend to “de-emphasize male-male competition and focus more on manipulation of the world through technology”. Parent-raised children can be reasonably expected to show greater within-group variation in beliefs and behaviours.
Peer-rearing produces different patterns. Potentially from a young age (as early as around two years old) the child finds themselves in a group, often with older siblings, who become the focus of the child’s social interaction. A group that has less status and power differences within it than are involved in parent-child interactions. Children learn that there are “many sources of food and desirables other than their parents”. Peer-raised children learn to network (who people are, what they have, how they are disposed towards them); that resources are acquired by manipulating social relations. They learn that “resources are not scarce and can be acquired through persuasion”.
The acquisition of culture within the peer group can also be expected to generate less variation in beliefs and behaviours. (It is a long-standing pattern that any organisations seeking to impose uniformity of outlook tend to be inherently suspicious, even hostile, to family autonomy and seek to undermine the authority and independence of families.)
Shifts in the activities of parents are likely to also shift societies from having children being parent-raised to being them peer-raised. In foraging communities, the shift to sedentism leads to longer foraging trips by males and more intense food acquisition and processing by females, as consumption shifts to more-effort foods. This leads to less parental attention to children, leading to more peer-raising. A mechanism that “may account for why sociocultural change seems to occur so quickly once hunter-gatherers become sedentary”.
Peer-raising typically has quite different effects on boys and girls. Girls are typically assigned as caretakers, contributing to “girls having attitudes favoring nurturance and prosocial behaviors … [and] more restricted spatial ranges”. Fathers being away for extended periods of time “is associated with boys who have poor attitudes towards females, who are aggressive and competitive towards other males, and who, when grown, give little attention to their offspring, encouraging a continuation of peer-rearing”. A pattern we can see in contemporary societies in deprived urban communities.
In sedentary societies, adolescent male peer groups have greater importance than in mobile societies, with more violent initiations and harsher punishments. “These competitive groups define a boy’s success in life more than in mobile societies where, presumably, fathers are more often present.” Street gangs are peer groups with added income or self-protection element
Cross-cultural surveys have found that “when men spend a lot of time with their offspring and cooperate in child rearing, there is less cultural emphasis on competition”. If men spend more time away from children, “there is a general physical separation of male and female tasks, and competition among men is encouraged”. (This could be a bit chicken-and-egg, if presumptively male tasks are such that they have to be done elsewhere.) “Partially as a response to male behavior, peer-raised girls show expression of sexual interest and assumption of sexual activity early in life, while also showing negative attitudes towards males and a poor ability to establish long term relationships with one male”.
Shifts in adult labour patterns can be “expected to have dramatic effects on enculturation and hence on cultural change”. These patterns clearly have implications well beyond foraging societies. Much of the literature on fatherlessness, for example, reads as the difference between parent-raised and peer-raised children. A sole parent clearly has less potential to counter-balance peer effects than do two parents.
In complex societies, peer groups may vary considerably. Much of the motivation to get students into “good” schools (whether public or private) is to ensure that they have a better quality peer group. Peer group effects also complicate trying tease out the specific effects of a school or teaching on education outcomes.
One of the counterpoints raised to the literature on fatherlessness is the claim, famously made in psychology Judith Rich Harris’s book The Nurture Assumption, that if one control for income/socio-economic status, the negative effects of sole-parenthood disappear. This is a classic problem of co-dependent variables. Being a sole-parent family tends to greatly affect (i.e. lower) household income and socio-economic status. Normal regression techniques are not analytically reliable in such circumstances. One has to use techniques such as comparing single-parent with two-parent families who are in the same income range. When that is done, the dis-advantaging tendencies of being raised by sole-parent families become quite clear: as one would expect. (For those interested in pursuing this further, the footnoted citations in this essay provide a useful place to start.)
The anthropological evidence also lends support to identifying fatherlessness as a negative factor in raising children. With much of the effects of fatherlessness being due to the effects of peer groups lacking competition from family life, particularly for boys. This obviously has implications for socially-deprived urban neighbourhoods and other localities suffering from absent fathers. Elijah Anderson’s classic study Code of the Streets (a useful summary essay is here) is very much congruent with this anthropological literature. J.D.Vance’s Hillbilly Elegy also touches on these issues, as does the excellent study Trump’s Democrats.
The developing pattern in many Western societies of marriage (and fatherhood) being strong in the upper reaches of society but decaying in the lower reaches is yet another socially-polarising factor in such societies.