Mother bodies, father bodies

Carolyn Moynihan
3 July 2014
Reproduced with Permission

Sometime during the last half century the strange idea that there is no difference between mothers and fathers when it comes to parenting - or none that cannot be eliminated by a social effort - gained currency. Moms can go out to work to bring home the bacon while dads stay home and tell their toddlers the story of the Three Little Pigs. Dads can nurture their children and moms can discipline them. Two dads or two moms are just as good for raising children as a mom and a dad. It's all about socially conditioned roles, isn't it?

No, it's not. Bodies make a difference. A real difference. A new report from the Institute for American Values drawing on the work of leading scholars from the natural and social sciences presents ten significant findings about the complementary nature of mothering and fathering - and the vital interaction of these roles with the body and the brain. It is immensely important background information for the debate over same-sex marriage because that is built on the premise that there is no difference between the child-raising abilities of men and women.

Here's a summary of the main points of Mother Bodies, Father Bodies, by Kathleen Kovner Kline and W. Bradford Wilcox . The report is published by the Institute for American Values .

1. Motherhood changes women's bodies and their brains.

Motherhood changes the female brain and body beyond pregnancy and lactation.

The physical changes that accompany pregnancy and childbirth are familiar to everyone, at least from the outside. The mother's own experience is much richer, demanding and lasting. Long after the child grows up, a woman's body will still bear the marks of pregnancy, childbirth, and nursing. But science is showing us that motherhood changes women even more profoundly, from the inside out.

It is seldom recognized that for humans and other mammals, the most critical organ for reproductive success just might be the brain. For mammal mothers, caring for their babies requires focused attention and an increased awareness of the environment.

Mothers must guard their young against predators and other threats. They must also feed them, which makes finding food sources and maintaining food stores a constant challenge. To raise their young successfully mammalian females require the cognitive capacity not only to solve problems, but to solve multiple problems simultaneously - what some now refer to as "multitasking."

Though they have their limitations, rat studies have revealed how oestrogen, the primary female hormone, can increase brain growth in areas involved in learning, especially spatial memory. One study showed that rats with the most mothering experience (multi-moms - with more than two litters) learned most efficiently and retained their knowledge longest.

The multi-moms triumphed too in studies of physical ability, balance, co-ordination, and strength. Their brains even displayed less of the protein found in Alzheimer's disease, suggesting a possible brain-protecting effect of motherhood.

Researchers say that these effects may be produced not just by the nurturing experience or by the biochemicals stimulated by it, but by the interplay of both.

2. Fatherhood and the male body.

Fatherhood changes the male brain and body as males spend time with their mate and child.

Men typically appear to experience a drop in testosterone after becoming fathers, especially if they are living with the mother of their offspring. This is important because it is associated with more responsive parenting. Animal studies give some insights:

Some biological changes seem to come from exposure to the mother of their offspring. Others seem to come from actively caring for their offspring. In fact, it now appears that first-time fathers begin to experience hormonal changes before the birth of their offspring. Researchers speculate that these changes may occur in reaction to scents emitted from the expecting partners and from affectionate interaction with the partner herself.

What's more, fathers with prior infant care experience showed these changes earlier in their mate's pregnancy. After birth, fathers that care for their young show, like mothers, greater boldness, food-finding and problem-solving ability.

Other changes in the mammalian father's brain direct him to take more care of his mate and family and make him less vulnerable to distractions from other females. The brains of experienced fathers show an increase in receptivity to vasopressin, which along with oxcytocin and prolactin is associated with parent-child bonding. For men, too, these changes may have lasting benefits such as warding off age-related decline.

3. Co-operative breeding

Human mothers need help. The theory of kin altruism reinforces the idea that such help is most likely to come from the father and other family members. For our foremothers to attract mates who would be committed to their offspring they had to be selective.

Because sex is one of the most valuable reproductive resources women can offer, they have evolved psychological mechanisms that cause them to resist giving it away indiscriminately. Requiring love, sincerity, and kindness is a way of securing a commitment of resources commensurate with the value of the resource that women give to men.

On the basis of their distinctive biological endowments and psychological orientations as well as social roles men and women developed different parenting strengths:

Fathers, for instance, can translate their more aggressive orientation into the protection of their daughters and - as a consequence - girls who grow up with their fathers are more likely to delay sexual activity and childbearing. Mothers, in turn, can translate their superior ability to regulate emotion to establish a strong attachment with their children, which, in turn, provides their children with a secure emotional base for navigating the emotional and social challenges of life.

The expectations of the surrounding society play an important role:

For instance, men are more likely to invest in one mate and in one set of children when they have a high degree of paternity certainty, when a culture demands monogamy of them, and when their paternal investment increases the likelihood of their offspring's survival. It appears that some aspects of contemporary social life favor high parental investments, while others do not.

4. Gender socialization is not an adult conspiracy.

Humans, uniquely, attach powerful psychological and social meaning to being male or female. It is universal, for example, that women tend to invest more in parenting, especially of young children. Also universal is the socialisation of girls and boys - by their parents in the first place - to identify with their given gender.

In one analysis of 158 studies of socialization of children, the only significant common effect was parents' encouragement of gender-typed behavior in their children.

This process is continued by the wider society, which tends to channel boys and girls towards particular types of social roles and activities. All this is, of course, now open to question and being intentionally changed. However,

Gender socialization is not merely an "adult conspiracy," as some social constructionists might suggest. Cross-culturally, children themselves, as early as two years of age, show a clear preference for same-sexed peers. This gender segregation is also seen in many species of nonhuman primates. Children elicit gender-typical behavior from adults, and continue to function as "gender police" of their peers, sternly enforcing codes of appropriate and forbidden gender-specific behaviors. Boys appear more resistant to nontraditional gender attitudes than girls.

There are differences between cultures, and also within cultures shaped by things like education and social class. But in the end, the body gives a powerful message about gender:

Finally, all cultures acknowledge the undeniable gender differences related to childbearing. Pregnancy is the crossroads at which the most dramatic differences between genders appear, and these substantial changes in parents, especially women, have a formative impact on children.

5. Mothers and fathers are similar.

The psychologist Diana Baumrind has coined the term "authoritative parenting". She found that an approach to parenting that combines high levels of affection and involvement, the requisite measure of structure, and clear and consistent discipline was associated with the best outcomes for children. Social science research also indicates that children have the best psychological outcomes when their parents share an authoritative approach to parenting. Importantly:

Recent research has made clear that mothers and fathers alike can be authoritative parents. Fathers can be very involved with and affectionate toward their children, just as mothers can be firm disciplinarians. Both mothers and fathers can take partial or primary responsibility for a range of parental tasks - from managing their children's health care to directing extracurricular activities.

Findings from psychology and sociology show substantial similarity between mothers and fathers in responding to newborns and in their relative contributions to the welfare of adolescents and young adults. Their unique inputs, however, remained significant.

6. But mothers and fathers are also different.

Although mothers contribute more to family finances now than they did 50 years ago, in households headed by two married parents, fathers provide the lion's share. In 2012, husbands in married-couple families earned about 69 percent of the income.

And despite the fact that mothers are spending more time working outside the home, mothers today invest more hours in parenting than mothers did a generation or two ago, and they continue to outpace fathers, even though fathers' contribution to parenting has increased enormously. The ratio of mother to father primary time (one-on-one) with children fell from 5.6 in 1975 to 2.3 in 2003.

When it comes to basic care-giving and housework, mothers continue to take the lead and fathers take a helping role under their wives' directions. Mothers are the household managers.

Moms and dads also differ in their style of parenting. With an infant or toddler, for example, a father's "hallmark style of interaction is physical play that is characterized by arousal, excitement and unpredictability," whereas a mother is more likely to attend to feeding, diapering, and emotional security. There seem to be biological and not just social factors at work here. Gendered differences continue in interactions with older children.

Gender differences are also evident when it comes to discipline. Mothers tend to do more when it comes to setting limits and imposing penalties on children for misbehavior. But even though fathers are less likely to impose discipline on their children, when they do so, they tend to be firmer disciplinarians. To sum up the differences:

In numerous studies, fathers are noted to be the more physical, playful, surprising, challenging, and risk-oriented parent. The father's style of interaction seems geared to push children out of the nest. By contrast, mothers seem to be the more verbal, affectionate, predictable, comforting, and protective parent. Their style of interaction seems geared to make children feel at home in the nest. Taken together, these two diverse parenting styles supply children with a varied parenting diet.

7. Together, mothers and fathers create a parental synergy.

From pregnancy, when paternal support can improve physical and emotional outcomes for both mother and child, through the teenage years, the complementary input of mothers and fathers creates a synergy which optimises well-being and social competence in children.

In many ways, nature biologically attunes the mother to be the predominant caretaker during her offspring's first few months of life. … Mothers, especially experienced ones, do seem to be primed to provide the kind of sensitive and responsive care that infants need. However, fathers and others can share in providing this type of optimal care.

Their relative contribution differs throughout the child's and family's development. Maternal care is particularly helpful in fostering language development, emotional self-knowledge, and communication skills among children. Mothers' abilities are critical to the emotional well-being of their children; fathers have a more important role in establishing a climate of order and self-control in families and their involvement with their children is associated with academic success.

One study found that boys in single-mother homes were more than twice as likely to end up in jail or prison before they turned 30, compared to boys who were raised by their mother and father.

It is not just boys who benefit from paternal involvement when it comes to steering clear of trouble. Girls who receive high levels of attention and affection from their fathers are markedly less likely to be sexually active and to become pregnant as teen- agers.91 When dealing with the opposite sex, girls with engaged fathers benefit from a stronger "internal locus of control" and the sense that they are loved and appreciated by their fathers. In contrast, girls with absent or disengaged fathers are much more likely to seek out the attentions of a partner and to become pregnant.

8. Marriage, children, mothers, and fathers

Mothers and fathers are more likely to share in the tasks of parenthood when they are married to each other. One family scholar points out that "fathering is uniquely sensitive to the quality and stability of the relationship with the mother, and any work on father involvement must include an understanding of the relational triangle of mother, father, and child."

Marriage matters for mothers, too. Not only does a spouse share the tasks and burdens of parenting, but also the pleasures and affections that are characteristic of a woman's relationship with her infant are correlated with the quality of her marital relationship. The emotional support that a mother receives is often central to care- giving sensitivity that she displays towards her infant.

Why marriage? In many other species the male acts as progenitor and little else. But the long dependency of the human child made it necessary for the father to support the mother.

She needs a helpmate, someone to cooperate with her to feed and protect these vulnerable creatures. She needs someone she can trust and count on, someone who has an intense interest in her as well as in the child. In short, as a species, "to increase the likelihood of survival and success, the human infant needs a father and the human mother needs a mate." Long ago, societies started to call this thing "marriage."

9. Affection, sex, and cuddling make happy couples and cement stable families.

Among mammals that maintain strong pair bonds, scientists have discovered extensive courtship behaviors between the male and female. The pair bond itself seems to be strengthened and reinforced by physiological changes within the male and female that come from proximity, physical affection, and sexual activity. Animal studies show the neurotransmitter oxytocin in females and vasopressin in males play a key role.

Anthropological studies and brain research are revealing that this social act of pair bonding also has biological roots in humans. It starts with sex.

Of course, sex can be pleasurable and the requisite for reproduction. But this intense attraction to one another over time serves perhaps an even larger purpose. [David] Blankenhorn notes it is the couple's ongoing emotional entanglement and interest in one another that helps to create the couple that will raise the child. Ongoing sexual interest brings the father into the mother-child dyad. It promotes bonds between parents. It helps to establish a particular family structure: a lasting pair bond that bridges the sexual divide and creates fathers for children.

10. Families benefit when women and men are able to approach motherhood and fatherhood in different ways.

Sociologists W. Bradford Wilcox and Jeffrey Dew have explored the impact of gender on the division of parenting labor, family-work strategies, and marital quality among married couples. They find that, "most parents - including most mothers - do not wish to pursue an egalitarian work-family strategy where both parents work full-time."

They argue that a broadly neotraditional set of arrangements now characterize the lives of most married mothers and fathers in the U.S. They are "neo" in the sense that fathers are doing much more childcare now than they did forty years ago, most mothers work in the paid work force, and most married parents endorse egalitarian gender role attitudes. But they are also "traditional" in the sense that mothers still do markedly more childcare than fathers, most mothers do not work full-time, and most married mothers indicate that they would prefer to work part-time or stay at home.

The transition to parenthood can pose a real challenge to the quality of married life, but, says psychiatrist Scott Halzman, couples need to work through these challenges, in large part because "research indicates the profound benefit of a child being raised with both parents."

How can this be done? First, research indicates that couples do better when they recognize that the challenges they face adjusting to parenthood are common. Second, couples do better when they receive support from friends and family, for instance, with babysitting help that allows them to maintain time for couple-centered activities.

Finally, Haltzman believes that efforts to educate couples about gender differences in parenting will be helpful in providing husbands and wives with a new appreciation of the unique contributions they both make to the welfare of their children. Or, in Haltzman's words, "efforts should be made to educate society at large, and parents in particular, that gender differences in parents are real, and, rather than be extinguished or ignored, they should be embraced."


At a time when parenthood is typically intense, expensive and relatively shorter in lifespan, couples need an adaptable recipe that can help them understand the key ingredients and pathways to thriving for themselves and their children. The two main ingredients are normally a mother and a father "Of course, you can also cook without those particular ingredients - you can use substitutes, or leave something out, and often get good results, but it can be harder." In other words some things change, but others stay the same - in particular the body, with its capacity for motherhood or fatherhood and not just for sex.