7.4 Family behaviour
A number of aspects of human behaviour as individuals and within families have an evolutionary explanation. These behaviours are seen as being adaptive in the evolutionary past, leading to grater reproductive success. However, some predispositions are not necessarily appropriate in contemporary society, and may indeed be positively undesirable as discussed in Section 7.6. Importantly, the behaviours are not necessarily inevitable or pre-determined—they are predispositions that can be consciously controlled, and the laws, norms, values and culture of societies are important in channelling them in more desirable directions. Nevertheless, an appreciation of the biological imperatives underlying behaviours, such as a preference for caring for relatives rather than strangers, can help both in devising policy and understanding its limitations.
7.4.1 Altruism
Relatives share genes, so a gene for altruism towards kin can benefit a copy of itself. Co-operation and altruism are thus explained by the success of genes that cause relatives to look after each other because they share the same genes.
Both cognition and emotion foster the reproduction of genes. People in all societies define themselves in terms of their kinship—their parentage, family ties and ancestry. People also have emotional bonds with their kin, showing them more tolerance, trust and goodwill than towards strangers.
But the level of altruism directed at kin depends on the nearness of the relationship, and the probability that the kindness will help to reproduce one’s own genes. In evolutionary terms, familial love is correlated with the probability that loving acts would enhance the probability of benefiting copies of one’s genes. A genetic predisposition to help other people will spread because altruists will be helped when needed, while selfish individuals who do not help others will not be helped when they need it. Altruism has thus been described the mechanism by which DNA multiplies itself through a network of relatives.
7.4.2 Sex/gender roles
Differences in the roles of the sexes are persistent and universal. Some of these are likely be very ancient and shared with many birds and mammals—females nurture babies while males are concerned with status and dominance hierarchies and compete for access to females. Others are likely to be related to historical roles—males hunted and women gathered—and the environmental context.
Dimorphism in labour may be due to male-female complementarity in household provisioning and child-rearing. A mother is typically the primary care-giver and protector of a baby—she is present, hormonally primed, capable of lactation, sensitive to infant signals, related to the baby and has a big stake in the baby’s survival (Hrdy 2000). Maternal responsiveness to its needs attaches the infant to its mother and vice versa. The closer connection of women to their babies is likely to be an evolved response, since indifference would have been disadvantageous in reproductive terms. The very experience of carrying and giving birth is likely to trigger nurturing feelings in mothers, while other factors trigger these feelings in fathers (Miller 2001).
Evolution has provided a limited role for a father to care for an unweaned baby. In all societies women take primary responsibility for infant care and continue to provide solid food beyond weaning. Infants show greater fear of strange males than strange females. Mothers abandon children less frequently than fathers and display more grief than fathers at the loss of a child (Campbell 1999). However, it is not inevitable that mothers alone should care for babies—where safe child-care is available from benign, committed and interested caretakers (usually female kin), mothers will use it. They will even use less-than-ideal carers when it is better than the available alternatives.
Evolutionary theory suggests that part of the gender gap in the modern work environment might be the result of differential reproductive strategies followed by men and women over the course of human evolution and may thus be a product of natural selection (Winterhalder and Smith 2000). The evolutionary view suggests not that men and women have different abilities but that they have different ambitions. Whereas men’s reproductive success depended on competing politically for status and economically for wealth, women’s reproductive success depended on selecting the right mates and nurturing children.
Evolutionary theory predicts that men will tend to be more status-seeking, risk-taking, aggressive, dominance-seeking, achievement-oriented, persistent, single-minded, goal-oriented and competitive than women, since men’s work evolved and continues to be shaped by showing off to signal information about the individual (Hawkes and Bird 2002). The tendency towards risk-taking at work may mean that men typically achieve higher positions with higher pay than women in the labour market (Browne 1999, Browne 1995, 2002).
Men and women also value different aspects of jobs—men typically stress financial aspects, whereas women stress interpersonal aspects. Women will tend to be more nurturing, empathetic, co-operative and concerned with maintaining a web of relationships, as these traits would have been valuable in reproductive strategies in an ancestral environment.
Although evolutionary biology suggests women’s agendas do not often include climbing political or business ladders, it says nothing about how good they would be if they did (Ridley 1993). The similarities between men and women suggest that there are few occupations that will be the exclusive domain of one sex. However, many occupations are likely to be dominated by one sex or another if they are selected on the basis of individual preferences and abilities.
