Brain Rules for Baby (24 page)

This neural hardwiring suggests that there are aspects of a kid’s social skill set a parent just can’t control. It’s a big thing to say, but there may be a genetic component to the level of happiness your offspring can achieve. This somewhat scary idea deserves a more detailed explanation.

My mother says I was born laughing. Even though I entered the world prior to video cameras—or dads—in the delivery room, I do have a way to independently verify this observation. The pediatrician supervising my birth left a note, which my mother kept and I still have. The note says: “Baby appears to be laughing.”

That’s funny, for I love to laugh. I’m also an optimist. I tend to believe things will work out just fine, even when no shred of evidence warrants the attitude. My glass will always be half full, even if the glass is leaking. This predisposition has probably saved my emotional bacon more than once, given the number of years I have dealt with the often-depressing genetics of psychiatric disorders. If I was born laughing, was I also born happy? No, of course not. Most babies are born crying, and it doesn’t mean they are born depressed.

But is a tendency toward happiness or sadness genetic? Researcher Marty Seligman, one of the most well-regarded psychologists of the 20th century, thinks so. Seligman was among the first to directly link stress with clinical depression. His previous research involved shocking dogs to the point of learned helplessness; perhaps in reaction to that, many years ago he switched gears. His new topic? Learned optimism.

After years of researching optimism, Seligman concluded that everyone comes into this world with a happiness “set point”, something akin to a behavioral thermostat. This notion is based on the ideas of the late David Lykken, a behavioral geneticist at the University of Minnesota. Some children’s set points are programmed to high; they are naturally happy regardless of the circumstances life throws at them. Some children’s set points are programmed to low. They are by nature depressive, regardless of the circumstances life throws at them. Everybody else is in the middle.

This might sound a bit deterministic, and it is. You can move the
needle a few degrees, Seligman thinks, but for the most part, a person tends to stay around his or her God-given center. Seligman even has a formula, the Happiness Equation, to measure how happy people are. It is the sum of that set point, plus certain circumstances in your life, plus factors under your voluntary control.

Not everybody agrees with Seligman (the Happiness Equation has elicited special criticism). A preponderance of evidence suggests there is something to this set-point idea, but it needs work. To date, no neurological regions have been found devoted exclusively to the thermostat. Or to being happy in general. At the molecular level, researchers have yet to isolate a “happiness” gene or its thermostatic regulators, though researchers are working on both. We’ll take a closer look at these genes at the end of the chapter.

All of this work—starting with Baby 19, the distressed girl at the beginning of this chapter—suggests that genetic influences play an active role in our ability to experience sustained happiness.

Parents have known for centuries that babies come to this world with an inborn temperament. Scientist Jerome Kagan, who studied Baby 19, was the first to prove it. Human temperament is a complex, multidimensional concept—a child’s characteristic way of responding emotionally and behaviorally to external events. These responses are fairly fixed and innate; you can observe them in your baby soon after he or she is born.

Parents often confuse temperament with personality, but from a research perspective they aren’t the same thing. Experimental psychologists often describe personality in much more mutable terms, as behavior shaped primarily by parental and cultural factors. Personality is influenced by temperament the same way a house is influenced by its foundation. Many researchers believe temperament provides the emotional and behavioral building blocks upon which personalities are constructed.

Kagan was interested in one layer of temperament: how babies reacted when exposed to new things. He noticed that most babies took new things in stride, gazing calmly at new toys, curious and attentive to new inputs. But some babies were much edgier, more irritable. Kagan wanted to find a few of these more sensitive souls and follow them as they grew up. Babies 1 through 18 fit the first model just fine. These calm babies are said to have low-reactive temperaments. Baby 19 was completely different. She, and babies like her, have high-reactive temperaments.

The behavior remains remarkably stable over time, as Kagan found in his most well-known experiment. The study is still ongoing, having survived even the old sage’s retirement (a colleague has taken it over). The experiment enrolled 500 kids, starting at 4 months of age, who were coded for low reactivity or high reactivity. He retested these same kids at ages 4, 7, 11 and 15; some beyond that. Kagan found that babies coded as highly reactive were four times more likely than controls to be behaviorally inhibited by age 4, exhibiting classic Baby 19 behavior. By age 7, half of these kids had developed some form of anxiety, compared with 10 percent of the controls. There is almost no crossover. In another study of 400 kids, only 3 percent switched behaviors after five years. Kagan calls this the long shadow of temperament.

 

A researcher friend of mine has two little girls, ages 6 and 9 as of this writing, and their temperaments could not be more Kaganesque. The 6-year-old is little Miss Sunshine, socially fearless, prone to taking risks, ebullient, confident. She will charge into a playroom full
of strangers, initiate two conversations at once, quickly survey all the toys in the room, and then lock down on the dolls, playing for hours. Her big sister is the opposite. She seems fearful, tentative, cautiously tiptoeing into the same playroom after only reluctantly leaving her mother’s side. She then finds some safe corner and sits there. She shows no interest in exploring, hardly speaks at all, and appears scared if somebody tries to talk to her. My friends have their own Baby 19.

Will you have one, too? You stand a 1 in 5 chance. High-reactives composed about 20 percent of the population in Kagan’s studies.

But how a highly reactive baby turns out depends on many things. Every brain is wired differently, so not every brain state sparks the same behavior. That’s an important point. On top of that, high vs. low reactivity is only one dimension of temperament. Researchers look at everything from types of distress to attention span to sociability to activity level to the regularity of bodily functions. Studies like Kagan’s make conclusions about tendencies, not destinies. The data do not forecast what these children will become so much as they predict what they will NOT become. Highly reactive infants will not grow up to be exuberant, outgoing, bubbly, or bold. The older daughter will never become the younger daughter.

And if your infant is highly reactive? She might seem hard to parent, but there’s a silver lining. As these highly reactive children navigated through school, Kagan noticed, most were academically successful, even if they were a bucket of nerves. They made lots of friends. They were less likely to experiment with drugs, get pregnant, or drive recklessly. We think that’s because of an anxiety-driven need to acquire compensatory mechanisms. Kagan regularly employed high-reactives during his research career.“I always look for high reactives, he told the
New York Times.
“They’re compulsive, and they don’t make errors; they’re careful when they’re coding data.”

Why are fussy babies later the most likely to comply with parental wishes, be better socialized, and get the best grades? Because they
are the most sensitive to their environments, even if they snarl about being guided all the way. As long as you play an active, loving role in shaping behavior, even the most emotionally finicky among us will grow up well.

So you can see temperament at birth, and it remains stable over time. Does that mean temperament is completely controlled by genes? Hardly. As we saw with the ice-storm children in the Pregnancy chapter, it is possible to create a stressed baby simply by increasing the mother’s stress hormones—not a double helix in sight. The involvement of genes is a scientific question, not a scientific fact. Happily, it is being researched.

Studies of twins so far show that there is no one gene responsible for temperament. (Gene work almost always begins with twins, the gold standard being twins separated at birth and raised in different households.) When you look at the temperaments of identical twins, the degree of resemblance, the correlation, is about 0.4. This means there is probably some genetic contribution, but it is not a slam-dunk. For fraternal twins and non-twin siblings, the correlation is between 0.15 and 0.18, even less of a slam-dunk.

But a few genes have been isolated that might help explain one of the most baffling phenomena in all of developmental psychology: the resilient kid.

Milo’s father drank like a drain, then he’d hit anything that moved. Milo generally was exempted from the abuse. His sisters weren’t, though. The dad regularly raped Milo’s older sisters, which Milo, at age 6, would occasionally witness. Whether or not he was drunk, he beat Milo’s mom. She became cold and uncaring, not given to bandaging the wounds of her children, emotional or physical. One day
she got sick of this treatment and took off in the family car with a waiting boyfriend, never to return. Enraged, the dad broke the boy’s nose. From then on, Milo took his mom’s place as the family punching bag. His dad fell apart completely in the ensuing years, embarking on alcohol-and-drug fueled orgies and petty crimes. One day, when Milo was 16, his dad told him to come upstairs. As Milo did, his dad blew his own brains out. You’d think Milo’s future would have collapsed under the weight of this excruciating past. But that’s not what happened.

Milo had a head for numbers. He excelled at school, especially math. At age 14, Milo started running the household, taking money from his passed-out dad’s pocket to buy groceries. He also began tutoring his older sisters, who, not surprisingly, had fallen behind in their class work. Milo made it onto the honor role, became student-body president, qualified for and received college scholarships, and got a bachelor’s degree in business. Like a splinter in his finger, these early memories continue to irritate Milo. But they haven’t stopped him. As of this writing, Milo is a teetotaling, married father of two and the owner of his own car dealership. Quoting his favorite jazz musician, Miles Davis, Milo declared, “I wasn’t prepared to become a memory.”

How do we explain people like Milo? The short answer is that we can’t. Most kids in these situations duplicate their parent’s errors. But not all. Kids like Milo have an almost supernatural ability to rise above their circumstances. Some researchers have spent their entire careers trying to uncover the secrets of this resiliency. Geneticists recently have joined in, and their surprising results represent the cutting edge of behavioral research today.

Human behavior is almost always governed by the concerted teamwork of hundreds of genes. Nonetheless, as with any team sport, there are dominant players and minor ones. Though this work is at best preliminary, here are three genetic franchise players worth
keeping an eye on. They may have a role in shaping the temperament and personality of our children.

 

Children who are sexually abused, like Milo’s sisters, are at a much higher risk for becoming alcoholics, a fact researchers have known for years. They are also at greater risk for developing a debilitating mental health issue called antisocial personality disorder.

This is decidedly
not
true if the child has a variant of a gene called MAOA, which stands for monoamine oxidase A. There are two versions of this gene, one we’ll call “slow and the other “fast.” If the child has the slow version, she is surprisingly immune to the debilitating effects of her childhood. If she has the fast version, she falls into the stereotype. The fast version of this gene assists in hyper-stimulating the hippocampus and parts of the amygdala when a traumatic memory is remembered. The pain is too great; Jack Daniels is often turned to for relief. The slow version of this gene calms these systems remarkably. The traumas are there, but they lose their sting.

 

Milo’s mother was emotionally distant, cold and uncaring even when she was around. Such an environment often leads children, feeling deeply insecure, to act out in an effort to gain attention. The behavior is both understandable and obnoxious.

But not all kids who have such mothers have this insecurity, and a group of researchers in the Netherlands think they know why. A gene called DRD4, which stands for dopamine receptor D4, is deeply involved. It is one of a family of molecules capable of binding to the neurotransmitter dopamine and exerting specific physiological effects. If children have a variation of this gene called DRD4-7, this insecurity never develops. It’s as if the gene product coats the brain in Teflon. Kids without this variant have no such protection from the effects of insensitive parents; for kids who do, the increase is
sixfold
.

 

Researchers have known for years that some adults react to stressful, traumatic situations by taking them in stride. They may be debilitated for a while, but they eventually show solid signs of recovery. Other adults in the same situations experience deep depression and anxiety disorders, showing no signs of recovery after a few months. Some even commit suicide. These twin reactions are like grownup versions of Kagan’s low-reactive and high-reactive infants.