PDF Summary:The Blank Slate, by Steven Pinker

Throughout most of the 20th century, the mainstream intellectual view of human nature was that humans are benevolent blank slates, with immaterial souls distinct from their physical bodies. But, according to cognitive psychologist and public intellectual Steven Pinker, this view is mistaken. In The Blank Slate, Pinker argues that contemporary science shows instead that humans have an innate tendency toward conflict, personalities shaped by their genes, and entirely physical minds.

In this guide, we’ll outline the three components of the mainstream view of human nature—empiricism, romanticism, and dualism—that Pinker critiques. We’ll then discuss his scientific arguments against these components, and we’ll look at three parts of his alternative scientific conception of human nature. Finally, we’ll discuss what his scientific view means for gender differences, politics, and how we understand children.

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(Shortform note: While work in genetics supports the idea that core personality traits are heritable, and thus not dependent on environment alone, geneticists haven’t yet established the exact degree to which these traits are heritable. They estimate that 30 to 60% of the variance in personality traits is explained by our genes.)

Argument #2: Evolutionary Psychology Undermines Romanticism

Second, Pinker points out that evolutionary psychology is at odds with romanticism since evolution has steered the brain toward selfishness rather than romantic altruism.

He clarifies that, according to evolutionary psychology, the brain’s tendencies are byproducts of natural selection—the process by which genes that are most likely to be passed down to future generations are selected for and become more frequent. For example, because intelligent people are more likely to survive and therefore reproduce, genes for intelligence are selected for and—as intelligent people reproduce—become more frequent in the population.

Consequently, genes that encourage selfishness are likely to prevail over altruistic genes, because acting selfishly maximizes our chances of reproducing and passing down our genes. For instance, if our brains were predisposed to horde food, that would increase our chance of surviving long enough to reproduce.

Evolution and the Problem of Altruism

Although Pinker argues that evolutionary science is at odds with an altruistic view of human nature, some evolutionary biologists disagree. For example, in The Selfish Gene, Richard Dawkins acknowledges that although evolution generally predisposes us to be selfish, it can also instill altruism in settings where cooperation would help the whole group survive and reproduce.

Experts point out that if natural selection only acted at the level of individual organisms, we’d have no reason to expect altruism to evolve. But, because organisms of the same species have significant genetic overlaps, natural selection might program us to act benevolently toward those who share our genetic material. For this reason, humans might feel inclined to share their resources with members of their family or broader society, even though doing so could decrease their individual chances of surviving long enough to reproduce.

Argument #3: Cognitive Science Undermines Dualism

Finally, Pinker argues that cognitive science undermines dualism because it has shown that the mind can be a purely physical entity. Specifically, he contends that the computational theory of mind (CTM) provides a framework for understanding how the mind could arise in a physical world.

According to the CTM, the mind is analogous to a computer. Mental processes—such as reasoning, learning, and remembering—are computer processes that take inputs from the physical world and yield the correct output. For example, your eyes provide the input from processing a cherry blossom tree with pink flowers, leading to the output, which might be your belief that cherry blossoms are in bloom.

Crucially, Pinker points out that the CTM doesn’t require that any part of the mind be non-physical. After all, the inputs are first processed by physical body parts (like your eyes, ears, and skin). Then, the outputs are processed by physical structures in the brain.

The Chinese Room Argument Against the CTM

While Pinker suggests that the CTM refutes dualism, other scholars point out that the CTM is deeply contentious and subject to various counterarguments. The most famous of these is John Searle’s Chinese room argument, which holds that the CTM deeply misinterprets the nature of consciousness.

Searle first notes that, according to the CTM, consciousness is essentially a matter of various inputs leading to the “correct” outputs. For instance, the sensation of a burning hot stove (the input) might lead you to scream in pain (the output).

However, Searle uses a hypothetical scenario to argue that this picture of consciousness is incomplete: Imagine that a monolingual English speaker is locked in a room with a computer program that responds to Chinese characters as if in conversation. Outside the room, native Chinese speakers write Chinese messages on a piece of paper and slip it under the door. The English speaker then feeds the characters through the computer program, writes the program’s output characters that respond to the input message on the paper, and puts it back through the door. In this way, the Chinese speakers outside believe they’re conversing with a fellow Chinese speaker.

According to Searle, if the CTM were correct, then there should be some conscious entity in the room that understands Chinese—after all, the inputs yielded correct outputs. But, intuitively, neither the native English speaker nor the computer program actually understands Chinese, since the speaker just mindlessly slides Chinese characters under the door. For this reason, Searle concludes that consciousness can’t just be a matter of inputs yielding correct outputs (as the CTM proposes).

The Alternative Scientific View of Human Nature

Now that we’ve seen why Pinker rejects the mainstream view of human nature, we’ll consider three components of Pinker’s alternative conception of human nature—our accurate cognitive faculties, fallible consciences, and predisposition toward conflict.

Component #1: Accurate Mental Representations

Having argued that the mainstream view of human nature is false, Pinker seeks to replace it by showing that science establishes an alternative conception of human nature. In this section, we’ll look at the first component of the scientific view of human nature: accurate mental representations. Pinker argues that our brains have evolved to use categories, languages, and images to accurately represent the world.

Mental Representation #1: Categories

Pinker points out that our brains accurately sort things into different categories that help us reason about the world. For instance, your brain might categorize “large green things with scales and sharp teeth that swim underwater” as alligators, allowing you to identify alligators when you see them. Then, because you know that alligators are dangerous, this categorization allows you to respond appropriately when you see an alligator—whether that means running away or choosing not to engage.

(Shortform note: Social scientists note that we also categorize people by forming various social categories to which they belong. Although this helps children understand the world around them by, for instance, sorting individuals into different races, genders, and socioeconomic groups, it can also lead to harmful prejudices. For example, children might subconsciously form problematic racial biases as they learn to categorize people on racial grounds.)

Mental Representation #2: Language

In addition, Pinker writes that our brains have the capacity for language that allows us to accurately represent the world. Unlike postmodernists, who allege that language is merely a consistent system with no connection to the actual world, Pinker argues that we intuitively grasp the connection between our words and our world. For example, we often lament situations in which we can’t find the words to describe our experiences, but this presupposes that we can use language to accurately represent our experiences.

(Shortform note: Most philosophers of language agree with Pinker’s claim that language allows us to represent the world. According to these philosophers, language allows us to express propositions—meaningful ideas about the world that can either be true or false. For this reason, speakers of two different languages can still express the same proposition. For instance, an English speaker saying “snow is white” and a German speaker saying “Schnee ist weiss” express the same proposition.)

Mental Representation #3: Images

Finally, Pinker argues that we use images to faithfully capture the world. These images can be physical, like photographs, or mental representations, like when you imagine an apple. Once again, he notes that according to postmodernists, images have no connection to the external world; postmodernist theory holds that images are equivalent to reality, rather than representative of reality. But Pinker notes that this thesis contradicts our practice of critiquing images as unrealistic—for example, we might critique a painting of a celebrity if it doesn’t resemble them. Contrary to the postmodernist view, this practice presupposes that images can accurately resemble the world.

(Shortform note: In The Master and His Emissary, Iain McGilchrist joins Pinker in critiquing postmodernism, adding that the postmodernist view of images harms our ability to appreciate art. According to McGilchrist, postmodernists began to value “art for art’s sake” instead of recognizing that art is supposed to reflect some feature of reality. In turn, postmodernist artists often preferred abstract works that lack meaning.)

Component #2: Fallible Moral Judgments

While these mental representations help us understand the physical world, Pinker argues that another aspect of human nature helps us understand the world of morality—our conscience. According to Pinker, the human conscience evolved as a fallible way of grounding our moral judgments.

Pinker writes that, just like the rest of the human mind, our conscience evolved as a combination of neural circuits designed to help us reproduce. For this reason, we often deem actions immoral if they harm our ability to pass down our genetic material. For example, we would be outraged if a member of our family or community were murdered, and it’s clear that murdering someone who shares our genes would make it harder to pass down those genes.

However, Pinker argues that because our conscience has an evolutionary origin, we’re prone to mistakes when actions that aren’t actually immoral harm our ability to pass down our genes. For instance, he notes that most people have a moral aversion to incest between siblings—an action that can lead to genetic defects if siblings reproduce. But, according to Pinker, many ethicists believe that incest can be permissible under the correct conditions (for example, if both adults are consenting and using contraception).

Evolutionary Arguments Against Moral Realism

While Pinker argues that the evolutionary origin of our conscience means that some of our moral judgments are suspect, other moral philosophers go a step further, arguing that all of our moral judgments are faulty. According to their evolutionary debunking arguments, our capacity for moral reasoning evolved to enhance our genetic fitness—our ability to pass our genes down to future generations. However, they warn that we have no reason to think that the moral judgments that enhance genetic fitness are also true.

For instance, according to this logic, we don’t have any reason to think that it’s true that killing innocent people is immoral. Similarly, there’s no reason to believe it’s true that incest between siblings is immoral.

The upshot is that morality’s alleged evolutionary origin should lead to universal moral skepticism. These philosophers contend that, rather than viewing our moral intuitions as reliable guides to truth, we should instead view them as useful tools for passing down our genes.

Component #3: Predisposition Toward Conflict

In addition to describing our tendency to make fallible moral judgments, Pinker argues that we’re predisposed toward conflict because nobody shares our exact genetic interests.

To start, Pinker reminds us that according to evolutionary theory, natural selection has made it more likely we’ll pass down genes that enhance our genetic fitness (that is, make us more likely to reproduce). For this reason, genes that lead us to act in our own self-interest are passed down, as these genes make it more likely that we’ll reproduce.

(Shortform note: Although Pinker is correct that natural selection often favors genes that make us act in our own self-interest, experts point out that maladaptive traits—those that are actively harmful to our reproductive fitness—can also arise through evolution. For example, while a peacock’s colorful tail originally arose to impress potential mates, it can also make peacocks more salient to predators, hurting their survival chances.)

The upshot is that we’re predisposed toward conflict because acting in our own self-interest often requires us to act against the best interests of others. For instance, siblings within families are likely to vie for parental attention because this attention is beneficial for their development but is a finite resource.

(Shortform note: In other words, to borrow from game theoretic language, our self-interest is often a zero-sum game—a game in which one party’s gain necessarily equals the other party’s loss.)

The Implications of the Scientific View of Human Nature

Having established some of the components of Pinker’s scientific conception of human nature, we’ll now turn to its implications. In particular, we’ll examine arguments that some differences in male and female minds are rooted in genetics, political conservatism is better-founded than progressivism, and children’s personalities are largely heritable.

Implication #1: Genes Shape Some Cognitive Differences Between Males and Females

According to Pinker, the scientific view of human nature sheds light on the hot-button issue of gender. In particular, he argues that this account of human nature shows that some differences in men’s and women’s minds have roots in genetics, in contrast with the empiricist idea that gender differences are caused by socialization alone.

(Shortform note: In his book, Pinker largely uses the terms “gender” and “sex” interchangeably. However, it’s widely accepted in health care and other fields that these are distinct terms. “Sex” refers to biological features such as sexual anatomy and chromosomes. Doctors typically assign babies the sex of male, female, or intersex. By contrast, gender is a social construct; biology doesn’t determine it. People’s genders—such as male, female, and nonbinary—are based on their personal experiences as well as social and cultural norms. To align with these definitions, in this guide, we’ll use terms such as “sex,” “genetically male,” and “genetically female” to refer to “sex,” and we’ll use terms like “female”, “boy” and “nonbinary” when referring to gender.)

Pinker cites scientific studies refuting the empiricist idea that socialization alone causes gender differences. For example, one study examined 25 genetically male children born without a penis due to a medical condition. They were castrated and brought up as girls. The study found that all of these children exhibited traditionally male characteristics (like roughhousing) and half of them declared themselves boys without knowing of their condition. According to Pinker, if gender differences were caused only by culture, this outcome would be unexpected.

(Shortform note: Other experts point out that, in light of the study Pinker cites, health-care professionals have largely stopped recommending raising genetically male infants (ones with X and Y chromosomes) as females. In particular, while 54% of infants with the condition Pinker describes were raised as females between 1985 and 1992, only 6% were raised as females between 2001 and 2008.)

In practice, Pinker suggests that the gender gap—that many careers have a disproportionately low percentage of women—could have a partially genetic explanation. For example, he notes that the higher percentage of male mathematicians and engineers could be partially due to the fact that, across different cultures, boys tend to have slightly better mathematical and spatial reasoning skills than girls from a young age.

(Shortform note: The idea that men are better at certain skills like math is sometimes used to explain why men’s pay is typically higher than women’s, even for equivalent work. But some experts point out that the differences in math scores between boys and girls in many countries are too small to explain anything but a marginal difference in pay. For instance, in some countries like Moldova and Qatar, a gender pay gap persists despite almost no difference in math test scores between boys and girls.)

Pinker clarifies that such genetically rooted cognitive differences between men and women aren’t evidence of one gender’s superiority. Relatedly, any such differences aren’t grounds for gender discrimination. This takeaway aligns with his argument against empiricism: that discrimination is unjustifiable regardless of whether innate differences exist between people.

(Shortform note: Feminist theorists share Pinker’s opposition to sexism—however, some would likely recommend scrutinizing the research Pinker relied on to arrive at these conclusions. Historian and feminist theorist Donna Haraway argues that what’s often presented as objective, neutral scientific knowledge is influenced by researchers’ identities and biases. She says that scholars can ethically produce knowledge by recognizing their limitations and biases, and we should be skeptical of the work of researchers who fail to do so.)

Applying this takeaway to the world of work, Pinker argues for equality of opportunity in employment—ensuring men and women have access to the same career opportunities—over equality of outcomes, or the idea of basing employment decisions on the goal of proportional representation. Given this, he says, we should focus on supporting policies that make it easier for men and women to thrive in the careers they choose—regardless of whether they choose those careers in equal numbers.

(Shortform note: Pinker’s emphasis on equality of opportunity between men and women overlooks people who fall outside of the gender binary, such as those who are nonbinary, genderfluid, and two-spirit. Policies that focus on the career success of only men and women risk excluding these other genders. How can employers include people who fall outside the gender binary in their equality-of-opportunity approaches? Experts recommend policies such as omitting gendered language from dress codes, having gender-inclusive restrooms, and not requiring people to disclose their gender during the hiring process.)

Implication #2: Political Conservatism Is Well-Founded

Pinker also contends that his account of human nature helps us assess the foundations of conservative and progressive political thought. He argues that his account of human nature shows that conservatism rests on a stronger foundation than progressivism, as conservatives have traditionally assumed that humans are inherently selfish and corruptible.

For context, Pinker explains that secular conservatives such as Edmund Burke have traditionally accepted the view that humans lack understanding and morality. Consequently, they prefer preserving current social traditions because they believe it’s difficult to find new social structures that can accommodate humans’ inherent selfishness and ignorance. For example, consider the tradition of the US’s electoral college, which elects the President via state delegates whose numbers aren’t perfectly proportional to state populations. Even if this was a suboptimal system, Burke might encourage retaining it because any replacement could be worse.

(Shortform note: Burke is perhaps best known for his reflections on the French Revolution, in which radical revolutionaries executed the French king and queen along with thousands of others during the Reign of Terror. According to Burke, this revolution illustrated humans’ ignorance (specifically ignorance about the concept of liberty) and their disregard for time-tested social structures that ensured a stable, moral society. In other words, Burke believed the revolution showcased the pitfalls of trying to overthrow existing societal structures. He concluded that we should be wary of radically changing society since the consequences can be worse than current societal flaws.)

Pinker points out that, by contrast, progressives like Rousseau have historically accepted that humans are malleable and any limits to our knowledge and morality come from flawed social structures. For this reason, progressives are quick to upend existing social conditions that they think are less than ideal.

Progressive Ideals in the Prison Abolition Movement

One particularly clear manifestation of this progressive approach is the police and prison abolition movement. As we explored earlier, according to this movement’s advocates, crime arises when society isn’t meeting the needs of its citizens—for example, by having an insufficient social safety net. So they contend that both police and prisons would be unnecessary in a society that properly supports its citizens.

Some critiques of this movement mirror a common critique of Rousseau’s ideas: that sweeping reforms can lead to unintended, negative consequences. For instance, historian Simon Schama analyzes how Rousseau’s ideas influenced the French Revolution, arguing that the revolution resulted in violence and authoritarianism rather than a utopian society. Similarly, some critics of the prison abolition movement argue that its fixation on the radical solution of abolishing prisons could scare off potential supporters who’d otherwise be in favor of decarceration efforts.

According to Pinker, it’s clear that the view of human nature that traditional conservatives accept is more accurate—for example, as we explored above, science has shown that humans are prone to conflict and have inherently fallible consciences, just as the conservative view assumes. The progressive view, on the other hand, accepts doctrines similar to empiricism and romanticism, which Pinker already argued are misguided.

Implication #3: Children’s Personalities Are Heritable

Finally, Pinker examines what his scientific account of human nature says about children. Although empiricists contend that children’s personalities depend heavily on their upbringing and home life, Pinker instead argues that children’s personality traits are heritable and their upbringing plays little role.

Pinker maintains that twin studies show that all personality traits are heritable to at least some extent. He explains that, because these twins aren’t raised in the same environment, any degree of similarity between them can only have genetic origins. When tested for various core traits (like intelligence, neuroticism, and agreeableness) these twins consistently show heritability values of around 0.5, meaning that 50% of the variation in each personality trait has a genetic origin.

(Shortform note: Even if our core personality traits are partially determined by our genetics, personality experts point out that many such traits can subtly change over our lifetimes. For example, they note that it’s common for extroverted individuals to grow gradually more introverted over time.)

Pinker points out that, by contrast, similar studies have shown that our family upbringing has almost negligible impact on our personality. For example, studies of adult siblings’ personality traits reveal that these siblings are similar regardless of whether they grew up in the same household. Adopted siblings, on the other hand, don’t demonstrate a higher average degree of similarity than two random strangers.

Non-Genetic Ways That Parents Influence Children

Some researchers have critiqued the model used to arrive at the heritability value of 0.5. They explain that this number averages genetic and environmental effects across a sample of people, failing to account for how individual characteristics alter how genes and upbringing influence personality. For example, saying that the heritability of patience is 50% doesn’t mean that any specific child’s patience level is 50% genetic.

When these researchers used a different model to estimate genetic and environmental effects on twins’ personalities, they found that teens’ perceptions of their relationships with their parents impacted to what extent genes influenced their personalities. This put the heritability of certain personality traits at a range of 20%-76%—higher for teens who felt their parents were proud of them and lower for teens who didn’t.

Beyond the question of how parents influence children’s personalities, psychologists have found that parents shape their children’s attachment styles—how their children relate to others in close relationships. To illustrate, if parents are emotionally unavailable and cold toward their children, those children are much more likely to become avoidant in their later relationships, meaning they tend to crave independence and have difficulty with trust and intimacy.