Behave: The Biology of Humans at Our Best and Worst

by Robert M. Sapolsky

This is mediated by projections from an ancient, core brain structure, the “periaqueductal gray” (PAG); stimulation of the PAG can evoke panic attacks, and it is enlarged in people with chronic panic attacks.

What does the frontal cortex do? Its list of expertise includes working memory, executive function (organizing knowledge strategically, and then initiating an action based on an executive decision), gratification postponement, long-term planning, regulation of emotions, and reining in impulsivity.

the frontal cortex makes you do the harder thing when it’s the right thing to do.

Testosterone makes us more willing to do what it takes to attain and maintain status. And the key point is what it takes. Engineer social circumstances right, and boosting testosterone levels during a challenge would make people compete like crazy to do the most acts of random kindness. In our world riddled with male violence, the problem isn’t that testosterone can increase levels of aggression. The problem is the frequency with which we reward aggression.

the brain is heavily influenced by genes. But from birth through young adulthood, the part of the human brain that most defines us is less a product of the genes with which you started life than of what life has thrown at you. Because it is the last to mature, by definition the frontal cortex is the brain region least constrained by genes and most sculpted by experience.

In the 1980s, the Romanian dictator Nicolae Ceauşescu banned contraceptives and abortions for any women who had not yet given birth to five children. Soon institutions filled with thousands of infants and kids abandoned by impoverished families (many intent on reclaiming their child when finances improved).* Kids were warehoused in overwhelmed institutions, resulting in severe neglect and deprivation. The story broke after Ceauşescu’s 1989 overthrow. Many kids were adopted by Westerners, and international attention led to some improvements in the institutions. Since then, children adopted in the West, those eventually returned to their families, and those who remained institutionalized have been studied, primarily by Charles Nelson of Harvard.

The picture is complicated further—AIS individuals raised female have higher-than-expected rates of being gay, and of having an other-than-female or neither-female-nor-male-sex/gender self-identification.

Chapter 11 examines the psychology with which we think about people of different socioeconomic status; no surprise, in unequal societies, people on top generate justifications for their status.

Our brains form Us/Them dichotomies (henceforth, “Us/Them-ing,” for brevity) with stunning speed.2 As discussed in chapter 3, fifty-millisecond exposure to the face of someone of another race activates the amygdala, while failing to activate the fusiform face area as much as same-race faces do—all within a few hundred milliseconds.

Numerous experiments confirm that the brain differentially processes images within milliseconds based on minimal cues about race or gender.

Racial dichotomies are formed during a crucial developmental period. As evidence, children adopted before age eight by someone of a different race develop the expertise at face recognition of the adoptive parent’s race.

Thus, the strength of Us/Them-ing is shown by: (a) the speed and minimal sensory stimuli required for the brain to process group differences; (b) the unconscious automaticity of such processes; (c) its presence in other primates and very young humans; and (d) the tendency to group according to arbitrary differences, and to then imbue those markers with power.

Nonetheless, no other primate kills over ideology, theology, or aesthetics.

Despite the importance of thought in Us/Them-ing, its core is emotional and automatic.

In the words of Berreby in his book, “Stereotyping isn’t a case of lazy, short-cutting cognition. It isn’t conscious cognition at all.”

The strongest evidence that abrasive Them-ing originates in emotions and automatic processes is that supposed rational cognitions about Thems can be unconsciously manipulated. In an example cited earlier, subjects unconsciously primed about “loyalty” sit closer to Us-es and farther from Thems, while those primed about “equality” do the opposite.

INTELLIGENCE Oh, what the hell? Let’s begin with something inflammatory. Starting with Theodor Adorno in the 1950s, people have suggested that lower intelligence predicts adherence to conservative ideology.33 Some but not all studies since then have supported this conclusion. More consistent has been a link between lower intelligence and a subtype of conservatism, namely right-wing authoritarianism (RWA, a fondness for hierarchy). One particularly thorough demonstration of this involved more than fifteen thousand subjects in the UK and United States; importantly, the links among low IQ, RWA, and intergroup prejudice were there after controlling for education and socioeconomic status. The standard, convincing explanation for the link is that RWA provides simple answers, ideal for people with poor abstract reasoning skills. INTELLECTUAL