The Book in Three Sentences

The two classic drivers of human development are nature (genes) and nurture (environment). Many people mistakenly believe nurture only refers to how parents raise their children. Although children do learn things from their parents, they learn far more from their peers. The world that children share with their peer group is what shapes their behavior, modifies the characteristics they were born with, and determines the sort of people they will be when they grow up.

The Nurture Assumption summary

This is my book summary of The Nurture Assumption by Judith Rich Harris. My notes are informal and often contain quotes from the book as well as my own thoughts. This summary also includes key lessons and important passages from the book.

  • The two classical drives of human development have been thought to be nature and nurture, genes and environment.
  • The nurture assumption is that, aside from their genes, what influences the way children develop is the way their parents bring them up. In other words, we assume parents are the whole environment, when in reality the environment includes much more.
  • Fascinating: before Freud and behaviorism, clinical psychology books didn’t even talk about parental impact on children. It wasn’t until Freud that parental nurture exploded onto the scene.
  • In many ways, children do not imitate their parents. They don’t drive cars, light matches, leave home whenever they please, and so on. You’ll also notice many kids of immigrants don’t have accents while their parents do.
  • If you start out thinking there is a “good” and a “bad” approach to anything, then you are clouding you judgment. You have to release your attachment to certain sides of the argument and start with a blank slate if you want to discover the truth.
  • In general, you should put little stock in correlation research and trust experiments much more. (Most child psychology research is correlational. Child psychologists usually look for trends rather than setting up experiments.)
  • There are two correlations that show up often enough that we can say they are true (although they may not be particularly strong). First, parents who do a good job of managing their lives and dealing with problems generally have children who do the same. Second, child who are shown love and affection are likely to grow up with cordial, well-adjusted relationships.
  • Overall, heredity accounts for approximately 50 percent of behavioral differences among people. Environment accounts for the other 50 percent.
  • Children come into the world already different from one another thanks to their genes. Then, parents treat their children differently precisely because they think and act in different ways. Genetics leads to different parenting styles.
  • Identical twins raised on the same home are no more alike than identical twins raised in different homes. Both sets of twins have small personalities and small differences. It appears genetics accounts for nearly all the differences.
  • If parents treat different children in different ways, are they simply responding to genetic differences in the children? Or are they causing differences by the different treatment they give each child?
  • Birth order is one factor that produces very different micro-environments for each child to develop in. Any differences in personality are known as birth order effects. Interestingly, researchers have found no link between birth order and behavioral differences.
  • The problem many of these socialization issues run into is what Karl Popper cited: you can’t prove it, but more importantly you can’t disprove it. You can’t call something science if there is no way to test whether or not it is false.
  • All people behavior differently in different situations. This is true even of babies.
  • What you learn in one context will not necessarily work in another.
  • Most children have at least two distinct environments: the home and the world outside the home.
  • The patterns of behavior acquired in the family are often different from the patterns of behavior acquired with peers.
  • A parent’s behavior toward a child impacts how the child behaves in the presence of the parent or in contexts that are associated with the parent.
  • One of the book’s key points: although children do learn things from their parents, they do not only learn things from their parents.
  • People tend to be drawn to others like themselves. For example, it is likely your childhood friend will the same age, sex, race, and have similar values. It is worth noting that children and adults are very unlike each other in size, intelligence, power, freedom and more.
  • “It takes a village to raise a child.” But only because you need a village to have a large enough play group. The bulk of child socialization occurs within the play group with their peers.
  • Laughter is the favorite weapon of the group. It is used by kids around the world to keep others in line with their expectations and norms.
  • Research found that peer acceptance or rejection was associated with overall life status adjustment in adulthood. However, having or not having friends during grade school was not associated with life status adjustment in adulthood. Social comparison is a key part of discovering and finding yourself, regardless of what your friendships look like.
  • Margaret Mead’s definition of culture: “The systematic body of learned behavior which is transmitted from parents to children.” This definition is correct about learned behaviors being passed down, but mistakenly assumes this process only occurs from parents to children.
  • Cultures are not passed on from parents to children. We know this because children of immigrant parents adopt the culture of their peers. This means neither the parent’s child rearing methods nor the imitation of the parents by the child are dominant factors in passing on culture.
  • Cultures are not passed on by all of the adults in a society. We know this because cases where children are of a different culture than the adults (for example, deaf children) take on the culture of their peers and not the culture of the adults. Thus, the society-wide adult culture is not a dominant factor in passing on culture.
  • According to the author, cultures are passed on by the children’s peer group. She calls this “group socialization theory.”
  • The world that children share with their peers is what shapes their behavior and modifies the characteristics they were born with and, hence, determines the sort of people they will be when they grow up.
  • A child’s goal is not to become a successful adult no more than a prisoner’s goal is to become a successful guard. A child’s goal is to be a successful child. Thus, the influence of peers is stronger than the influence of adults.
  • Your power to influence your children’s friendships drops significantly over time. Once they are 10 years old, you have very little influence over their peer group.
  • One of the best strategies parents have at their disposal for influencing their kids is to move to a different school district. This often hurts kids who rely on their peer group for good standing, but if the kid is beaten down by other kids and his status amongst peers is zero, then he has very little to lose.
  • Like other aspects of personality, self-esteem is tied to the social context through which it was acquired. A person can feel good about herself with friends and bad about herself at home, or vice versa.
  • Self-esteem is a function of ones status in their peer group. Low status in the peer group can wreck a person’s personality.
  • The parents have limited control over the child within the peer group, but one way they can influence peer group status is by making sure their children look normal and attractive. Normal and attractive means wearing the clothes other kids are wearing, getting braces, or going to the dermatologist to treat acne.
  • We drastically underestimate the fact that children are born different. We do not appreciate the genetic differences enough.
  • The main reason babies become smart adult is not because their parents read to them or hang fancy mobiles above their head (if so, our ancient ancestors would never become intelligent). It is because smart babies come from smart parents and thus have smart genes.
  • Sleep training is a completely cultural construct and a product of our modern society. Babies never slept in separate rooms until recently. In hunter gatherer societies, a crying baby would never be left alone. It was always with the tribe. It is not natural to let your baby cry. It is natural to let it sleep with the parent.
  • Is there an evolutionary reason why parenting should be hard? It doesn’t seem so. In fact, parenting should be easy and pleasurable. This would ensure we would want to parent our offspring. Maybe if parenting is a chore, you’re working too hard at it.
  • Our society is obsessed with equality and fairness, but there is nothing about nature that states equality must be the rule. In fact, it is far more natural to have inequality in some cases.
  • Quality time is an interesting concept. Most kids prefer to spend quality time with their peers, not their parents. And yet, parents are supposed to feel guilty if they don’t spend enough time with their kids.
  • Parenting is a job where sincerity and hard work do not guarantee success. Through no fault of their own, good parents sometimes have bad kids.
  • Love your kids because kids are lovable, not because some expert prescribes it. You can neither perfect nor ruin your kids, they are not yours to perfect or ruin. Just love them.

The Nurture Assumption by Judith Rich Harris

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