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Themes and Colors
Incentives Theme Icon
Irrational Behavior, Experts, and “Conventional Wisdom” Theme Icon
Morality and Prescriptive vs. Descriptive Thinking Theme Icon
Nature vs. Nurture Theme Icon
Crime Theme Icon
LitCharts assigns a color and icon to each theme in Freakonomics, which you can use to track the themes throughout the work.
Nature vs. Nurture Theme Icon

Much of Freakonomics is concerned with the difference between nature—the genetic qualities with which a human being is born—and nurture—the environmental influences that shape a human being’s character and behavior. By studying the relative influence of nature and nurture in children, the book reaches some interesting conclusions about both, while also suggesting some of the strengths and weaknesses of economics itself.

In order to assess the relative importance of nature and nurture, Levitt and Dubner use statistical methods to imitate the format of a scientific experiment. Using data gathered by the Department of Education, among many other institutions, the authors apply “regression” analysis in order to understand the relationship between many different variables. With the data gathered by the Department of Education, for example, it’s possible to find subjects that are statistically identical, save for a few variables (for example, IQ, parents’ income level, etc.). By isolating these few variables, economists can mathematically test the strength of the correlation between the variables; in other words, they can determine if there is a positive or a negative relationship between the variables, or if the variables have no influence on one another. This process imitates the format of a science experiment by isolating specific variables, and studying how changes in one variable (the independent variable) correlate with changes in another variable (the dependent variable).

The results of Levitt and Dubner’s regression analysis suggest that nature and nurture both play some role in a human being’s growth and behavior. There are many situations in which the parents’ income and education level tend to “trickle down” to the child, regardless of the child’s genetics. For instance, when identical twins (i.e., children whose “nature” is identical) are adopted by different parents, the twin who’s adopted by the wealthier, more educated parents is more likely to go to college and get a higher-paying job. However, in the majority of the cases Levitt and Dubner analyze, nature seems to play the stronger role in determining a child’s academic success, future income level, health, happiness, and general development. Statistical analyses suggest that parenting methods, such as reading to one’s child, going to museums with the child, and spanking the child, have little to no correlation with the child’s development. On the other hand, parental qualities like education, age, and general optimism correlate strongly with a child’s development. This would seem to suggest that parents pass on their useful qualities to their children genetically (i.e., through nature).

The manner in which Levitt and Dubner reach their conclusions about nature’s superiority to nurture suggests some of the conceptual weaknesses of economics, however. Levitt and Dubner have no way of studying how, exactly, genetics influences human development; only biologists and geneticists can provide those details. Indeed, the only way that Levitt and Dubner can determine that genetics plays a greater role in human behavior than nurture is by process of elimination: i.e., the fact that parental behaviors don’t play as large a role in child development would seem to indicate that genetics do, without explaining exactly how. Furthermore, Levitt and Dubner are forced to admit that statistical analysis cannot predict how people are going to behave in the future; in other words, there is always an element of randomness that no analysis of nature or nurture can account for. For instance, a child with a good education and loving, wealthy, educated parents could still turn out to be a serious criminal for reasons that no statistical analysis could reveal (and in fact, one such child, Ted Kaczynski, grew up to be the Unabomber, a notorious terrorist). So even if economics can use mathematics to suggest that nature plays a greater role in human behavior than nurture does, the limits of economics itself might—by Levitt and Dubner’s own admission—cause us to take this hypothesis with a grain of salt. To understand human behavior, we need economics—but we also need genetics, anthropology, history, and many other areas of study.

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Nature vs. Nurture Quotes in Freakonomics

Below you will find the important quotes in Freakonomics related to the theme of Nature vs. Nurture.
Chapter 4 Quotes

Growing up in a single-parent home roughly doubles a child’s propensity to commit crime. So does having a teenage mother. Another study has shown that low maternal education is the single most powerful factor leading to criminality.
In other words, the very factors that drove millions of American women to have an abortion also seemed to predict that their children, had they been born, would have led unhappy and possibly criminal lives.

Page Number: 139
Explanation and Analysis:

In this passage, the authors reiterate some of the points they made in the Introduction about the relationship between the abortion rate and the crime rate in America. Statistically speaking, there is a high correlation between one’s likelihood of committing a crime and one’s family circumstances: mother’s age, being in a single-parent household, mother’s educational levels, etc. So it follows that legalizing abortions would have a profound negative influence on the crime rate: indeed, by the 1990s, the crime rate had gone down dramatically, supposedly reflecting the legalization of abortion in 1973.

This argument can be unpleasant, because it involves saying that people from certain backgrounds are more likely to commit crimes. Furthermore, Levitt and Dubner have come under a lot of fire for suggesting that abortions played a major role in the lowering crime rate. Yet they’re not saying that abortion should be used as a tool to fight crime, nor are they necessarily suggesting that abortion was the only factor in the lowering crime rate. Their duty as economists is to describe and interpret the data in an unbiased manner, even if their conclusions don’t please everyone.


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So even for someone who considers a fetus to be worth only one one-hundredth of a human being, the trade-off between higher abortion and lower crime is, by an economist's reckoning, terribly inefficient.

Page Number: 145
Explanation and Analysis:

At the end of the chapter, the authors double down on their controversial position on abortion, and make an even more controversial argument for measuring the “effectiveness” of the abortion rate’s influence on crime. The premise of their argument is that a fetus is worth one one-hundredth of an infant baby’s life. Therefore, it follows that economists can measure the “net” effectiveness of the abortion rate on crime, factoring in the premise that abortion is a form of murder (or rather, one hundred abortions are equivalent to the murder of one child). Overall, then, the abortion rate has been a highly “inefficient” way of fighting crime.

The authors’ argument could be interpreted as provocative, since it puts human life in overly mathematical, material terms, and judges these lives with bloodless words like “efficient” and “inefficient.” It’s likely that Levitt and Dubner know they’re being provocative by making observations about abortion—perhaps they are trying to rouse readers away from the conventional wisdom and toward a more objective, rational way of talking about the real world, or at least trying to keep them reading the book.

Chapter 5 Quotes

The typical parenting expert, like experts in other fields, is prone to sound exceedingly sure of himself. An expert doesn't so much argue the various sides of an issue as plant his flag firmly on one side. That's because an expert whose argument reeks of restraint or nuance often doesn't get much attention.

Page Number: 148
Explanation and Analysis:

In Chapter 5, the authors discuss some competing theories about how to raise a child. To begin with, however, the authors discuss the prevalence of experts on child rearing. As with the other experts who appear in Freakonomics, parenting experts often aren’t to be trusted. The vast majority of these figures, the authors allege, don’t really know how to raise a good child. On the contrary, parenting experts excel at seeming sure of themselves, and presenting complicated, nuanced arguments in overly simplistic forms. Parenting experts have a clear economic incentive for simplifying the truth—the simpler and more attractive their ideas, the more time they’ll get to spend on TV, or the better their books will sell. With such an economic incentive in place, parenting experts tailor their ideas to fit the conventional wisdom, eliminating nuance and ambiguity—i.e., exactly what John Kenneth Galbraith (who coined the term “conventional wisdom”) warned against.

A long line of studies, including research into twins who were separated at birth, had already concluded that genes alone are responsible for perhaps 50 percent of a child's personality and abilities.

Page Number: 154
Explanation and Analysis:

Before embarking on a detailed study of the effects of nurture on a child’s academic success, the authors make a few brief observations about the relationship between nature and nurture. They note the numerous studies that conclude that genetics plays a major role in a child’s development. Levitt and Dubner suggest that genetics accounts for perhaps fifty percent of a child’s personality and abilities—implying that the remaining half of a child’s life can be explained by studying nurture.

The passage is significant because it illustrates some of the limitations of economics as an intellectual discipline. The authors have no way of using economics to study how, precisely, genetics can influence a child’s personality—only biologists, geneticists, and other medical researchers could answer these questions. Instead of conducting in-depth studies of how genetics and nurture influence a child, Levitt and Dubner just analyze statistics describing how large groups of children have behaved under different circumstances. In a sense, then, economists have to study the roles of nature and nurture from the outside.

What appears to be an advantage gained by going to a new school isn’t connected to the new school at all. What this means is that the students—and parents—who choose to opt out tend to be smarter and more academically motivated to begin with. But statistically, they gained no academic benefit by changing schools.

Page Number: 160
Explanation and Analysis:

A study of the Chicago Public School (CPS) system yields some surprising results about the role of high school education on academic performance. The data suggested that there is no correlation between the high school a child attends and the child’s academic performance. In other words, two children with the same academic abilities (as measured by various tests) will tend to finish high school with the same academic abilities, even if they attend different Chicago schools.

The authors’ conclusions are surprising, since one would expect that high school attendance would at least play some role in academic performance. The authors clarify their point by adding some nuance to it: it is true that students who transfer to different high schools tend to outperform students who don’t take advantage of their option to transfer to a different school. But this doesn’t prove that particular high schools improve students’ academic performance. Rather, it just proves that there’s a selection bias in the process of transferring schools: the students who choose to switch schools in search of a better education are likely to 1) have intelligent parents who recognize the value of a good education, and 2) be more intelligent than the average high school student. In all, the CPS data suggests that academic performance reflects a student’s intelligence and talent far more than a teacher’s ability to educate.

The data reveal that black children who perform poorly in school do so not because they are black but because a black child is more likely to come from a low-income, low-education household. A typical black child and white child from the same socioeconomic background, however, have the same abilities in math and reading upon entering kindergarten.

Page Number: 166
Explanation and Analysis:

In this passage, the authors analyze the results of a Department of Education study of thousands of American school children. The study measured dozens of different variables—academic performance, family structure, income level, etc.—therefore, it can be used to analyze the influence of these variables on academic performance. The authors find that there is, contrary to some racist claims, no true “gap” between black and white students. While it is true that, on average, white students outperform black students on tests, the reason isn’t that black students are innately inferior to their white counterparts; rather, it’s that black students, on average, tend to have a lower economic background, and are more likely to be raised by a single parent. In short, the authors use statistics to disprove the racist lie that blacks are inferior to whites.

Chapter 6 Quotes

There is a clear pattern at play: once a name catches on among high-income, highly educated parents, it starts working its way down the socioeconomic ladder. Amber and Heather started out as high-end names, as did Stephanie and Brittany.

Page Number: 204
Explanation and Analysis:

At the end of the chapter, the authors identify a strange trend in naming: names that are initially popular among affluent families tend to “trickle down” to the middle and lower classes over a certain span of years. Thus, a name like “Heather” was popular in the 1970s and 80s among affluent families, but is now most common among working class families.

The passage emphasizes an important point about human behavior: humans seek the approval of their peers, and often act out of a desire for social prestige. Thus, people give their children affluent-sounding names in order to receive the social incentives of being perceived as a “fancy” family, or in the hopes that their children will grow up to achieve a higher level of wealth and status. However, the process of giving a child an affluent-sounding name is still subject to the laws of the market: the more people give their children such a name, the less social prestige it carries, until eventually, the name becomes associated with middle or working class families.

Epilogue Quotes

The second child, now twenty-eight years old, is Roland G. Fryer Jr., the Harvard economist studying black underachievement.
The white child also made it to Harvard. But soon after, things went badly for him. His name is Ted Kaczynski.

Related Characters: Roland Fryer , Ted Kaczynski
Related Symbols: The white child and the black child
Page Number: 211
Explanation and Analysis:

The book concludes with a description of the two “hypothetical” children discussed in the earlier chapters. As it turns out, these children weren’t hypothetical at all: the black child was Roland Fryer, while the white child was Ted Kaczynski, the Unabomber, one of the deadliest terrorists in American history.

On paper, Kaczynski had every conceivable advantage in life: whiteness, maleness, a brilliant mind, loving parents, an affluent background, etc. By contrast, Fryer had tremendous disadvantages: an abusive father, a poor neighborhood, racial oppression, etc. But where Kaczynski squandered his advantages and ended up becoming a dangerous murderer, Fryer overcame obstacles and became a great success at Harvard University. In all, the examples of Kazcynski and Fryer illustrate some of the limitations of economics. Economics is good at describing how, on average, a large group of people will behave. But when dealing with a small “sample size”—in this case, only two people—economics can’t predict what people will do. Kaczynski cannot be “explained” in terms of his background, his IQ, or other metrics. There is a limit, in short, to how much economics as a whole can tell us about people, and on the individual level there is always a level of randomness and other unknown factors that cannot be measured.