The Nurture Assumption Book Summary, by Judith Rich Harris

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1-Page Summary of The Nurture Assumption

Nature and Nurture

For a long time, experts believed that heredity and environment had the most impact on how people develop. However, current research suggests that while heredity is indeed important, nurture has little to no effect on development.

Socialization is how children become members of society. They must learn a lot to be socially adept, such as learning a language and dressing appropriately for their culture. However, the assumption that parents are responsible for socializing their children has little evidence behind it; in fact, genetics and peer groups play bigger roles than parenting does.

Research on socialization has been misleading. Many studies have failed to control for genetic influences, and therefore it’s possible that the children of well-socialized parents are more likely to be well-socialized because they inherited their genes from those parents. In addition, some things like physical appearance may not always translate into behavior or personality traits. For example, if one child is beautiful and another unattractive, they will probably receive different treatment by their parents even though they’re genetically similar. The research doesn’t account for this possibility.

Additionally, genetics can affect how children behave and the choices they make. Research has shown that even when twins are raised apart from each other, they often have very similar personalities and make similar choices in life. This suggests that controlling for genetic factors is critical to making any reliable conclusions about the effect of nurture on child development.

Fashions in Child Rearing

Child-rearing practices change frequently. They’re influenced by peer groups, especially among middle class whites in the United States. Breast-feeding is popular among well educated mothers and not as common with African American peers. Bottle feeding is more common in developing countries than breast feeding because it’s seen as fashionable even though bottle fed babies aren’t as healthy. Spanking or swatting children isn’t considered good child rearing practice among white, well educated U.S middle classes while other ethnic groups find it acceptable to spank their children if they misbehave.

Child-rearing has changed over time. Experts have advised both to be somewhat distant and unemotional, as well as to lavish affection upon children. Current thinking is that the best way to raise kids is in solid two-parent families, but at one point it was thought that sending young kids away to boarding schools was a good idea. The American upper middle class tends to follow what experts say because their peers define those things as normal or right.

The Importance of the Group

Humans and chimpanzees are similar in that they’re both social animals. They have certain social characteristics in common, such as distinguishing between members of their own groups and other groups, making war on other groups, sometimes planning engagements in advance, using stealth and guile. Jane Goodall witnessed a group of chimps massacre another smaller group with whom they were acquainted. In another case, when a crippled chimp tried to rejoin his group, the larger group attacked him.

Research shows that people are predisposed to form groups. They identify with their group and favor it over other groups, even if they don’t know the members of the other group. This is shown by a study in which participants were randomly assigned to one of two groups, then given the opportunity to give rewards to each group. Even though their own reward was unaffected by this decision, they still favored their own group. In another experiment conducted at Robbers Cave State Park in Oklahoma, hostility and violence broke out very quickly when boys formed into two groups.

Babies are very social at a young age and begin to imitate each other. They sort themselves into groups of people who have the same characteristics as they do. For example, if it’s an all-children group, then everyone is a child. Groups defined by things such as gender and age – women or men for example – are common in most societies even hunter-gatherer villages. However, thanks to agriculture which enables more people to live in one area, we’re able to create groups that define us based on our gender and age: girls versus boys; women versus men; etc… It’s interesting how we may decide whether we belong within those groups by looking at how much we resemble its members. Therefore, it makes sense why certain groups can influence you even though you don’t necessarily fit in with them because they can make you act like them (even if their not your own). A couple left their six year old son at a Tibetan monastery where he lived with multiple Tibetan boys who were training to become Buddhist monks although the Tibetans didn’t really accept him as one of his peers but he was still influenced by them nonetheless years later living back home with his wife who was also from Tibet he referred himself as “a Tibetan” instead of American despite being born here

How Groups Raise Children

The goal of children is not to be successful as adults, but rather to succeed in their childhood. In order for that to happen, they need the approval and acceptance of their peers. They don’t want to be held back because it means being an outcast in a group they’re unfamiliar with.

Group forces can be powerful in shaping certain behaviors. For example, African-American boys may reject academic success because they view it as “unAfrican American.” Their friends’ behavior also affects their decisions. Children are more likely to smoke if they have friends who do so, but whether or not their parents smoke does not matter. Some groups value criminal behavior and take risks. Juvenile delinquents who live with other juvenile delinquents are likely to become criminals again because of the group’s influence on them. If a child grows up in an area where crime is common, he or she will probably grow up to commit crimes too unless he or she moves somewhere else when he or she becomes an adult and has children of his own.

To effectively influence children, social programs need to be directed toward groups rather than individuals. Social groups transmit language, culture and values to children. It is noteworthy that historically black colleges produce the majority of prominent black intellectuals, and girls seem to do better in science and math in all-girl schools than co-ed schools because they are not distracted by boys or pressured by group norms against being smart. In a school with an all-black or all-female population, academic achievement is not defined as nonblack or unfeminine. Group norms do not discourage excellence; therefore it becomes easier for children to excel academically when their peers have similar goals and aspirations.

How to Raise Children

Parents have a limited ability to influence children’s development. Socialization researchers haven’t been able to prove that birth order, spanking or parental education are responsible for how children develop. Genes and environment matter in the long run, but not as much as peer groups do.

Therefore, parents should be aware of their limitations and think about the potential they have. One potential asset is that a family can become a group if the parent acts as its leader. Although this seems rare in Western culture, it’s not clear what the minimum number of members is needed to make a group work.

Parents can have the most influence on their children by choosing a good peer group for them. Parents should pick neighborhoods and schools where there are lots of kids who want to do well in school and be successful, rather than hanging out with friends who are into crime. It’s better if the neighborhood has few or no problems with crime, too.

Parents can help their kids fit in better. This is important because when children fit in, they feel more accepted and have higher self-esteem. To do this, parents should make sure that their child has good skin care (if necessary), straight teeth (if necessary), and a healthy weight (if necessary). Many of these things are considered desirable by groups of people, so it’s often the case where group acceptance leads to greater self-esteem for children.

In the natural order of things, dominance happens. Parents are supposed to be in charge and have authority over their children. They aren’t entertainers or playmates for their children; they’re there to take care of them and discipline them if necessary. In many societies, older siblings also have a dominant role with younger siblings because they’ve already been through that experience before and know what it’s like being the youngest sibling. It’s not surprising then that middle-class American parents don’t allow this hierarchy within families because we value equality so much, but it can cause problems for older siblings who don’t get the special treatment that could help soften the blow of feeling displaced by a new baby brother or sister (e.g., having more responsibility). Sibling rivalry doesn’t seem to happen in societies where an older sibling has authority over a younger one; instead, they tend to develop close bonds as brothers/sisters since those relationships mean something more than just two people living under one roof together.

The nurture assumption has been responsible for plenty of parental anxiety and distress. When children turn out badly, the nurture assumption says that it is the parents’ fault. But no evidence supports this idea. So, parents should stop worrying and do their best job to raise a child while recognizing their limits and acknowledging the power of peer groups in a child’s development. Children learn from peers as well as adults, so it’s important to make sure they’re exposed to good groups or avoid bad ones since kids will model themselves after those around them if given an opportunity.

Full Summary of The Nurture Assumption


As a parent, you can’t help but feel proud of your child. You’re also well-versed in parenting manuals and always set on doing the right thing.

But, as surprising as it may seem, parenting has little to do with a child’s personality! It seems like we believe that parents are the ones who shape their children. However, if this is not true and parents don’t determine how kids turn out, then who does? These questions will be answered by these key points.

In addition, you’ll learn about a boy raised as a girl and vice versa; the differences between identical twins who were separated at birth; and how two chimpanzees raised a human child.

Big Idea #1: The nurture assumption – that parenting plays the key role in a child’s development – is dead wrong.

We all have wondered about how we became the person we are today. This has led people to believe that our genes or upbringing play a large role in shaping us. However, most of us tend to lean towards the latter, nurture assumption because it’s more probable than nature (our genetics). It is also widely believed that parents shape their children’s personalities and characteristics. People tend to assume this because it seems logical for them as well as being a cultural norm.

However, as you’ll see, the evidence amassed by developmental psychologists in support of the “nurture assumption” has been biased from the beginning. The nurture assumption is a huge cultural myth because children are influenced by many people outside their family such as friends and teachers.

Because of the nature of scientific research, it’s hard to study the relationship between a child’s upbringing and her character. Scientists can’t just take 500 children away from their parents for the sake of research.

Instead of looking for a cause-and-effect relationship between shyness and punishment, researchers are content to look for correlations. For example, if a child is punished often, he or she tends to be shy. This makes it difficult to find other factors that could contribute to this correlation.

Big Idea #2: Compared to our genetic makeup, the home we’re raised in barely affects our character.

If you have siblings, then you probably feel like they’re nothing like you at times. But it’s not surprising that there are similarities between siblings because of their shared experiences growing up together.

Genes impact personality because they’re responsible for certain traits. For example, identical twins have the same genes and often end up with similar personalities.

The Minnesota Twin Family Study was conducted on two pairs of twins. They were genetically identical, but raised in very different environments. Despite the differences in their upbringings, they both developed similar habits and likes/dislikes as adults, such as biting their nails and driving the same car.

Not only did they have the same names, but their sons were also named James Allan and James Alan. That’s pretty amazing evidence of how genes influence our development. But it gets even more interesting: twins who grow up in different homes are just as similar to each other as those who grow up together. So if growing up together doesn’t make twins any more similar, what does? It turns out that having a lot in common is all about genetics—not upbringing or environment.

For instance, a study in Minnesota looked at the personality traits of twins and found that they were only 50% similar. This means that there was no significant difference between them and twins who grew up separately.

From the data above, we can infer that parents have little control over how their children turn out. However, this is hard to believe since everyday life influences a child’s character and behavior. We’ll explain why in the next key point.

Big Idea #3: Our behavior isn’t written in stone but adapts to the social context.

Have you ever tried to teach your cat that it’s OK to sleep in the same bed as you, as long as your partner isn’t there? Don’t do this because either way the cat will be uncomfortable and anxious.

Cats have instincts that tell them how to behave in certain situations. However, humans are different because we can learn new rules when a situation changes. For example, if you tie a ribbon on the leg of a six-month-old child and connect it to an object hanging above her, she will quickly figure out that she can move the object by moving her leg.

However, if the situation changes, say a child’s crib is moved to another room, they will realize that there isn’t a string and move on. Even when we are older, we assume that new rules apply in different situations.

That’s why we often alter our behavior to fit the situation. It makes sense because different situations have varying rewards and punishments associated with them.

For example, when a boy wants his mother to love him more than she loves his brother, he may act cute. However, if the same boy were acting in front of friends who would tease him for behaving like a baby, he wouldn’t do that because it’s not appropriate behavior for someone of his age.

It means that even if a child’s behavior is dependent on his parents in a certain situation, it doesn’t mean his personality is entirely determined by them. For instance, if the mother of a child who has been depressed for some time starts to smile again and interact more with her kid, he might start smiling as well when they’re together. But this same kid could be the happiest in the room at nursery school while playing with one of his warm caregivers.

So even if a child mimics his mother’s sadness, the sadness is not inherent to the child.

Big Idea #4: Children acquire language through imitation.

Have you ever been at the zoo and seen people imitate chimpanzees? Have you even imitated them yourself? Probably not, because humans are much more likely to imitate than chimpanzees. We learn to speak by copying others, so we have a natural tendency to imitate things that we see around us.

Some people hypothesized that children could acquire language skills by imitating others. This was later proven to be true, and it’s now known that the language a child learns is dependent on what they imitate.

In the early 1930s, a psychologist named Winthrop Kellogg raised an infant chimpanzee in his home along with his son. The human child began to imitate the chimpanzee and eventually started speaking like one, for instance by barking when he was hungry.

Donald Trump did not learn to speak English quickly. In fact, at 19 months old, the average child has a vocabulary of about 50 words, but Donald only had three.

An experiment with a chimp named Donald showed that humans can learn to speak without the help of their parents. This is because when he was brought into contact with human playmates, they didn’t respond to “Chimpanzee.”

Children have the ability to learn languages without being taught. For instance, they might be exposed to a language at school or from their friends. They might even pick up a language from their parents if those parents aren’t native speakers of that language.

Big Idea #5: For a child to become a stable adult, no mommy is needed.

If you walk into a kindergarten classroom, you will see children clinging to their mothers’ legs and begging them not to leave. Why do kids do that? Toddlers don’t like being left alone because they are afraid of the unknown. They need reassurance and comfort from their parents or guardians.

Young children prefer to have their mothers around because they provide security. As we all know, the mother-child relationship is powerful and important for survival. In a study, researchers placed two babies in a room with their mothers and found that even when the children were busy playing with one another, they closely watched their mothers to make sure they stayed close by. This shows us that young children value being close to their mothers more than anything else. However, peers can also substitute for this bond since it’s not as strong as others’.

Actually, how well we relate to others does not depend on our relationship with our mother or father. Peers can easily fill the same role for us; a study shows that children who lost their parents in concentration camps were able to stick together and show no signs of rivalry when playing. In fact, they would even hand food over to each other before eating themselves, which is unusual for children this young.

Essentially, the children were taking each other’s places as parents. They grew up healthy despite their traumatic pasts and are now well-adjusted adults. It makes sense that they preserved their ability to make close human relationships because of this unique experience.

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Big Idea #6: Girls and boys are different and it’s got nothing to do with how their parents treat them.

Parents try to encourage their children to play with toys that are meant for the opposite gender. Even though boys and girls have many similarities, they’re still different. Just look at human genetics: we share forty-five unisex chromosomes, and it’s just that tiny forty-sixth chromosome, the Y, that accounts for all of our differences.

Despite the fact that boys and girls are different, they have some things in common. For example, both genders have genitals (boys have penises and girls have vaginas). However, there are differences between them as well. For instance, a seven-month old boy lost his penis due to circumcision complications. His parents were advised by psychologists to turn him into a girl because it would be easier for him than dealing with the loss of his male genitalia. They did so by removing his testicles (which normally produce testosterone) and gave him female genitalia instead.

Despite efforts to help him, the boy never felt like a girl. In fact, he was so depressed that he tried to kill himself at 14. Later, it turned out that his identity had been misdiagnosed and he changed his gender.

Children don’t typically become masculine or feminine because of their parents. Rather, children take on those traits by interacting with other kids in school and elsewhere. This is because they relate to people who are the same age as them more than they do their own parents.

As a result, once children categorize themselves as boys or girls, they pay close attention to how boys and girls behave. They imitate the behavior of their gender group.

Big Idea #7: Children and teenagers want be like their peers, not adults.

Children grow up to be adults because they want to maintain their status in the group.

Children want to fit in with their peers, and the older ones tend to be more influential. In a group of children who are all about the same age, it is those who are physically and psychologically mature that hold higher status.

To avoid being treated poorly by their peers, children imitate those who are more mature. They do this because they equate age with status and don’t want to be humiliated by the group.

For example, a study found that kids in school felt being rejected by their peers was worse than losing a parent or going blind. In fact, this sense of belonging to a group makes teenagers rebellious because they don’t want to be adults.

Teenagers have their own groups and hate it when adults try to impose rules from the adult group. For example, a parent tells them how to dress, but they react by dressing in the opposite way so that they don’t look like part of that group.

Big Idea #8: Parents can become leaders of a family group, but it’s the exception to the rule.

So, does this mean that parents have no influence on how their children turn out? No. In general, a family isn’t a group and kids don’t strive to be like their parents. However, if there is a common goal or enemy for the members of the family then they might form into a group with shared traits and goals.

Take the example of twins who were separated at birth. One twin became a concert pianist while the other couldn’t play an instrument. The non-musical home was where the piano player grew up, and she wanted to stand out from her family by excelling in music.

In some cases, twins can become members of the same family. If they were adopted into families that are archenemies, then those families would be natural enemies.

Not only that, but it would seem more likely for the twin with a piano teacher as her mother to play the piano. This is because she’d strive to be like her mother by creating an us-versus-them mentality in which they become a group led by their parent.

Donald Thornton had a dream. He wanted his six daughters to succeed more than he did, so he told them that they were better than their peers and forced them to compete against each other.

Because of that, the daughters all became successful professionals.

The Nurture Assumption Book Summary, by Judith Rich Harris

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