07-womb-crib

A Seven Back to the Crib, Back to the Womb fter journeying to Planet Adolescence, we resume our basic approach. Our behavior—good, bad, or ambiguous—has occurred. Why? When seeking the roots of behavior, long before neurons or hormones come to mind, we typically look first at childhood. C COMPLEXIFICATION hildhood is obviously about increasing complexity in every realm of behavior, thought, and emotion. Crucially, such increasing complexity typically emerges in stereotypical, universal sequences of stages. Most child behavioral development research is implicitly stage oriented, concerning: (a) the sequence with which stages emerge; (b) how experience influences the speed and surety with which that sequential tape of maturation unreels; and (c) how this helps create the adult a child ultimately becomes. We start by examining the neurobiology of the “stage” nature of development. T A BRIEF TOUR OF BRAIN DEVELOPMENT he stages of human brain development make sense. A few weeks after conception, a wave of neurons are born and migrate to their correction locations. Around twenty weeks, there is a burst of synapse formation—neurons start talking to one another. And then axons start being wrapped in myelin, the glial cell insulation (forming “white matter”) that speeds up action. Neuron formation, migration, and synaptogenesis are mostly prenatal in humans.1 In contrast, there is little myelin at birth, particularly in evolutionarily newer brain regions; as we’ve seen, myelination proceeds for a quarter century. The stages of myelination and consequent functional development are stereotypical. For example, the cortical region central to language comprehension myelinates a few months earlier than that for language production—kids understand language before producing it. Myelination is most consequential when enwrapping the longest axons, in neurons that communicate the greatest distances. Thus myelination particularly facilitates brain regions talking to one another. No brain region is an island, and the formation of circuits connecting far-flung brain regions is crucial—how else can the frontal cortex use its few myelinated neurons to talk to neurons in the brain’s subbasement to make you toilet trained?2 As we saw, mammalian fetuses overproduce neurons and synapses; ineffective or unessential synapses and neurons are pruned, producing leaner, meaner, more efficient circuitry. To reiterate a theme from the last chapter, the later a particular brain region matures, the less it is shaped by genes and the more by environment.3 W STAGES hat stages of child development help explain the good/bad/in-between adult behavior that got the ball rolling in chapter 1? The mother of all developmental stage theories was supplied in 1923, pioneered by Jean Piaget’s clever, elegant experiments revealing four stages of cognitive development:4 Sensorimotor stage (birth to ~24 months). Thought concerns only what the child can directly sense and explore. During this stage, typically at around 8 months, children develop “object permanence,” understanding that even if they can’t see an object, it still exists—the infant can generate a mental image of something no longer there.* Preoperational stage (~2 to 7 years). The child can maintain ideas about how the world works without explicit examples in front of him. Thoughts are increasingly symbolic; imaginary play abounds. However, reasoning is intuitive—no logic, no cause and effect. This is when kids can’t yet demonstrate “conservation of volume.” Identical beakers A and B are filled with equal amounts of water. Pour the contents of beaker B into beaker C, which is taller and thinner. Ask the child, “Which has more water, A or C?” Kids in the preoperational stage use incorrect folk intuition—the water line in C is higher than that in A; it must contain more water. Concrete operational stage (7 to 12 years). Kids think logically, no longer falling for that different-shaped-beakers nonsense. However, generalizing logic from specific cases is iffy. As is abstract thinking—for example, proverbs are interpreted literally (“‘Birds of a feather flock together’ means that similar birds form flocks”). Formal operational stage (adolescence onward). Approaching adult levels of abstraction, reasoning, and metacognition. Kid playing hide-and-seek while in the “If I can’t see you (or even if I can’t see you as easily as usual), then you can’t see me” stage. Other aspects of cognitive development are also conceptualized in stages. An early stage occurs when toddlers form ego boundaries—“There is a ‘me,’ separate from everyone else.” A lack of ego boundaries is shown when a toddler isn’t all that solid on where he ends and Mommy starts—she’s cut her finger, and he claims his finger hurts.5 Next comes the stage of realizing that other individuals have different information than you do. Nine-month-olds look where someone points (as can other apes and dogs), knowing the pointer has information that they don’t. This is fueled by motivation: Where is that toy? Where’s she looking? Older kids understand more broadly that other people have different thoughts, beliefs, and knowledge than they, the landmark of achieving Theory of Mind (ToM).6 Here’s what not having ToM looks like. A two-year-old and an adult see a cookie placed in box A. The adult leaves, and the researcher switches the cookie to box B. Ask the child, “When that person comes back, where will he look for the cookie?” Box B—the child knows it’s there and thus everyone knows. Around age three or four the child can reason, “They’ll think it’s in A, even though I know it’s in B.” Shazam: ToM. Mastering such “false belief” tests is a major developmental landmark. ToM then progresses to fancier insightfulness—e.g., grasping irony, perspective taking, or secondary ToM (understanding person A’s ToM about person B).7 Various cortical regions mediate ToM: parts of the medial PFC (surprise!) and some new players, including the precuneus, the superior temporal sulcus, and the temporoparietal junction (TPJ). This is shown with neuroimaging; by ToM deficits if these regions are damaged (autistic individuals, who have limited ToM, have decreased gray matter and activity in the superior temporal sulcus); and by the fact that if you temporarily inactivate the TPJ, people don’t consider someone’s intentions when judging them morally.8 Thus there are stages of gaze following, followed by primary ToM, then secondary ToM, then perspective taking, with the speed of transitions influenced by experience (e.g., kids with older siblings achieve ToM earlier than average).9 Naturally, there are criticisms of stage approaches to cognitive development. One is at the heart of this book: a Piagetian framework sits in a “cognition” bucket, ignoring the impact of social and emotional factors. One example to be discussed in chapter 12 concerns preverbal infants, who sure don’t grasp transitivity (if A > B, and B > C, then A > C). Show a violation of transitivity in interactions between shapes on a screen (shape A should knock over shape C, but the opposite occurs), and the kid is unbothered, doesn’t look for long. But personify the shapes with eyes and a mouth, and now heart rate increases, the kid looks longer—“Whoa, character C is supposed to move out of character A’s way, not the reverse.” Humans understand logical operations between individuals earlier than between objects.10 Social and motivational state can shift cognitive stage as well. Rudiments of ToM are more demonstrable in chimps who are interacting with another chimp (versus a human) and if there is something motivating—food—involved.11 Emotion and affect can alter cognitive stage in remarkably local ways. I saw a wonderful example of this when my daughter displayed both ToM and failure of ToM in the same breath. She had changed preschools and was visiting her old class. She told everyone about life in her new school: “Then, after lunch, we play on the swings. There are swings at my new school. And then, after that, we go inside and Carolee reads us a story. Then, after that . . .” ToM: “play on the swings”—wait, they don’t know that my school has swings; I need to tell them. Failure of ToM: “Carolee reads us a story.” Carolee, the teacher at her new school. The same logic should apply—tell them who Carolee is. But because Carolee was the most wonderful teacher alive, ToM failed. Afterward I asked her, “Hey, why didn’t you tell everyone that Carolee is your teacher?” “Oh, everyone knows Carolee.” How could everyone not? Feeling Someone Else’s Pain ToM leads to a next step—people can have different feelings than me, including pained ones.12 This realization is not sufficient for empathy. After all, sociopaths, who pathologically lack empathy, use superb ToM to stay three manipulative, remorseless steps ahead of everyone. Nor is this realization strictly necessary for empathy, as kids too young for ToM show rudiments of feeling someone else’s pain—a toddler will try to comfort someone feigning crying, offering them her pacifier (and the empathy is rudimentary in that the toddler can’t imagine someone being comforted by different things than she is). Yes, very rudimentary. Maybe the toddler feels profound empathy. Or maybe she’s just distressed by the crying and is self-interestedly trying to quiet the adult. The childhood capacity for empathy progresses from feeling someone’s pain because you are them, to feeling for the other person, to feeling as them. The neurobiology of kid empathy makes sense. As introduced in chapter 2, in adults the anterior cingulate cortex activates when they see someone hurt. Ditto for the amygdala and insula, especially in instances of intentional harm— there is anger and disgust. PFC regions including the (emotional) vmPFC are on board. Observing physical pain (e.g., a finger being poked with a needle) produces a concrete, vicarious pattern: there is activation of the periaqueductal gray (PAG), a region central to your own pain perception, in parts of the sensory cortex receiving sensation from your own fingers, and in motor neurons that command your own fingers to move. You clench your fingers. Work by Jean Decety of the University of Chicago shows that when seven- year-olds watch someone in pain, activation is greatest in the more concrete regions—the PAG and the sensory and motor cortices—with PAG activity coupled to the minimal vmPFC activation there is. In older kids the vmPFC is coupled to increasingly activated limbic structures.13 And by adolescence the stronger vmPFC activation is coupled to ToM regions. What’s happening? Empathy is shifting from the concrete world of “Her finger must hurt, I’m suddenly conscious of my own finger” to ToM-ish focusing on the pokee’s emotions and experience. Young kids’ empathy doesn’t distinguish between intentional and unintentional harm or between harm to a person and to an object. Those distinctions emerge with age, around the time when the PAG part of empathic responses lessens and there is more engagement of the vmPFC and ToM regions; moreover, intentional harm now activates the amygdala and insula—anger and disgust at the perpetrator.* This is also when kids first distinguish between self- and other-inflicted pain. More sophistication—by around age seven, kids are expressing their empathy. By ages ten through twelve, empathy is more generalized and abstracted—empathy for “poor people,” rather than one individual (downside: this is also when kids first negatively stereotype categories of people). There are also hints of a sense of justice. Preschoolers tend to be egalitarians (e.g., it’s better that the friend gets a cookie when she does). But before we get carried away with the generosity of youth, there is already in-group bias; if the other child is a stranger, there is less egalitarianism.14 There is also a growing tendency of kids to respond to an injustice, when someone has been treated unfairly.15 But once again, before getting carried away with things, it comes with a bias. By ages four through six, kids in cultures from around the world respond negatively when they are the ones being shortchanged. It isn’t until ages eight through ten that kids respond negatively to someone else being treated unfairly. Moreover, there is considerable cross-cultural variability as to whether that later stage even emerges. The sense of justice in young kids is a very self-interested one. Soon after kids start responding negatively to someone else being treated unjustly, they begin attempting to rectify previous inequalities (“He should get more now because he got less before”).16 By preadolescence, egalitarianism gives way to acceptance of inequality because of merit or effort or for a greater good (“She should play more than him; she’s better/worked harder/is more important to the team”). Some kids even manage self-sacrifice for the greater good (“She should play more than me; she’s better”).* By adolescence, boys tend to accept inequality more than girls do, on utilitarian grounds. And both sexes are acquiescing to inequality as social convention—“Nothing can be done; that’s the way it is.” Moral Development With ToM, perspective taking, nuanced empathy, and a sense of justice in place, a child can start wrestling with telling right from wrong. Piaget emphasized how much kids’ play is about working out rules of appropriate behavior (rules that can differ from those of adults)* and how this involves stages of increasing complexity. This inspired a younger psychologist to investigate the topic more rigorously, with enormously influential consequences. In the 1950s Lawrence Kohlberg, then a graduate student at the University of Chicago and later a professor at Harvard, began formulating his monumental stages of moral development.17 Kids would be presented with moral conundrums. For example: The only dose of the only drug that will save a poor woman from dying is prohibitively expensive. Should she steal it? Why? Kohlberg concluded that moral judgment is a cognitive process, built around increasingly complex reasoning as kids mature. He proposed his famed three stages of moral development, each with two subparts. You’ve been told not to eat the tempting cookie in front of you. Should you eat it? Here are the painfully simplified stages of reasoning that go into the decision: Level 1: Should I Eat the Cookie? Preconventional Reasoning Stage 1. It depends. How likely am I to get punished? Being punished is unpleasant. Aggression typically peaks around ages two through four, after which kids are reined in by adults’ punishment (“Go sit in the corner”) and peers (i.e., being ostracized). Stage 2. It depends. If I refrain, will I get rewarded? Being rewarded is nice. Both stages are ego-oriented—obedience and self-interest (what’s in it for me?). Kohlberg found that children are typically at this level up to around ages eight through ten. Concern arises when aggression, particularly if callous and remorseless, doesn’t wane around these ages—this predicts an increased risk of adult sociopathy (aka antisocial personality).* Crucially, the behavior of future sociopaths seems impervious to negative feedback. As noted, high pain thresholds in sociopaths help explain their lack of empathy—it’s hard to feel someone else’s pain when you can’t feel your own. It also helps explain the imperviousness to negative feedback—why change your behavior if punishment doesn’t register? It is also around this stage that kids first reconcile after conflicts and derive comfort from reconciliation (e.g., decreasing glucocorticoid secretion and anxiety). Those benefits certainly suggest self-interest motivating reconciliation. This is shown in another, realpolitik way—kids reconcile more readily when the relationship matters to them. Level 2: Should I Eat the Cookie? Conventional Reasoning Stage 3. It depends. Who will be deprived if I do? Do I like them? What would other people do? What will people think of me for eating the cookie? It’s nice to think of others; it’s good to be well regarded. Stage 4. It depends. What’s the law? Are laws sacrosanct? What if everyone broke this law? It’s nice to have order. This is the judge who, considering predatory but legal lending practices by a bank, thinks, “I feel sorry for these victims . . . but I’m here to decide whether the bank broke a law . . . and it didn’t.” Conventional moral reasoning is relational (about your interactions with others and their consequences); most adolescents and adults are at this level. Level 3: Should I Eat the Cookie? Postconventional Reasoning Stage 5: It depends. What circumstances placed the cookie there? Who decided that I shouldn’t take it? Would I save a life by taking the cookie? It’s nice when clear rules are applied flexibly. Now the judge would think: “Yes, the bank’s actions were legal, but ultimately laws exist to protect the weak from the mighty, so signed contract or otherwise, that bank must be stopped.” Stage 6: It depends. Is my moral stance regarding this more vital than some law, a stance for which I’d pay the ultimate price if need be? It’s nice to know there are things for which I’d repeatedly sing, “We Will Not Be Moved.” This level is egoistic in that rules and their application come from within and reflect conscience, where a transgression exacts the ultimate cost—having to live with yourself afterward. It recognizes that being good and being law-abiding aren’t synonymous. As Woody Guthrie wrote in “Pretty Boy Floyd,” “I love a good man outside the law, just as much as I hate a bad man inside the law.”* Stage 6 is also egotistical, implicitly built on self-righteousness that trumps conventional petty bourgeois rule makers and bean counters, The Man, those sheep who just follow, etc. To quote Emerson, as is often done when considering the postconventional stage, “Every heroic act measures itself by its contempt of some external good.” Stage 6 reasoning can inspire. But it can also be insufferable, premised on “being good” and “being law abiding” as opposites. “To live outside the law, you must be honest,” wrote Bob Dylan. Kohlbergians found hardly anyone consistently at stage 5 or stage 6. — Kohlberg basically invented the scientific study of moral development in children. His stage model is so canonical that people in the business dis someone by suggesting they’re stuck in the primordial soup of a primitive Kohlberg stage. As we’ll see in chapter 12, there is even evidence that conservatives and liberals reason at different Kohlberg stages. Naturally, Kohlberg’s work has problems. The usual: Don’t take any stage model too seriously—there are exceptions, maturational transitions are not clean cut, and someone’s stage can be context dependent. The problem of tunnel vision and wrong emphases: Kohlberg initially studied the usual unrepresentative humans, namely Americans, and as we will see in later chapters, moral judgments differ cross-culturally. Moreover, subjects were male, something challenged in the 1980s by Carol Gilligan of NYU. The two agreed on the general sequence of stages. However, Gilligan and others showed that in making moral judgments, girls and women generally value care over justice, in contrast to boys and men. As a result, females tilt toward conventional thinking and its emphasis on relationships, while males tilt toward postconventional abstractions.18 The cognitive emphasis: Are moral judgments more the outcome of reasoning or of intuition and emotion? Kohlbergians favor the former. But as will be seen in chapter 13, plenty of organisms with limited cognitive skills, including young kids and nonhuman primates, display rudimentary senses of fairness and justice. Such findings anchor “social intuitionist” views of moral decision making, associated with psychologists Martin Hoffman and Jonathan Haidt, both of NYU.19 Naturally, the question becomes how moral reasoning and moral in