The Confidence Code by Katty Kay, Claire Shipman Page B

another, even more essential tie between us, one he discovered. The nimble rhesus monkey is the only primate that shares with us a particular gene variation that researchers are coming to see as essential to personality formation. The gene is called SLC6A4, or the serotonin transporter gene, and it directly affects confidence.
    We’d heard of serotonin, and you probably have, too. It has a big impact on mood and behavior; more of it can make you feel calm and happy. Prozac and all of its pharmaceutical relatives boost serotonin levels. Serotonin, in short, is good stuff and SLC6A4 is the gene that regulates our serotonin levels by recycling it through our system.
    This serotonin transporter gene comes in a few varieties, or in scientific terms, it has a polymorphism, which means it plays favorites; some of us have more efficient versions of it than others. One of the variations is made up of two short strands, which is fairly rare, but people with that genetic hand process serotonin badly, magnifying their risk of depression and anxiety. Another version contains a long and a short strand, which means better, but still inefficient, serotonin use. The third variant contains two long strands, which allows for the best use of the hormone. The people with that variant, scientists believe, are more naturally resilient, which is a key criterion for confidence.
    Dozens of studies have examined the SLC6A4 gene in humans. Most have demonstrated clear ties to depression and anxiety disorders and, recently, as scientists have turned toward the study of healthy mental attributes, the gene has been linked with happiness and optimism. Experts like Suomi, who know their way backwards and forwards around the gene, say it’s clear that serotonin, especially in its ability to inhibit anxiety, sets the stage for confidence.
    Years ago, when he saw the early research, Suomi, who had already conducted decades of meticulously documented behavioral studies of his monkeys, started to suspect the serotonin transporter gene might play a role in what he was seeing. He ran DNA tests on the whole bunch, looking for the serotonin gene. The genetics, when cross-referenced with all of his mounds of data, accurately predicted the behavior he had already recorded: which monkeys had been born depressed, more withdrawn and anxious, and which monkeys were more resilient. He’d hit the jackpot.
    We gazed around his office, which was jammed with files and decorated with photos of his brood, many of which were vintage eighties and hanging askew. One, in particular, bears an uncanny resemblance to photos of our children we display around the house— Cocoabean, one of the first monkeys born in Maryland, is taking a glorious leap into the pond of the field station, while her furry pal Eric looks on. The careful nurturing, observation and testing that’s been Suomi’s life and passion for decades has produced results even he could not have imagined. Happily for us, that work offers a new lens on the genetic origins of confidence, even if in humans confident behavior would seem to be more subtle and varied than it is in monkeys. Being on the retiring side himself, Suomi admitted a certain fascination with our topic. Ruddy-faced, mild-mannered, and sporting a comfortable blue cardigan, he turned his bespectacled gaze away from his research and toward us, and started to describe the variations in confidence he has come to observe.
    He has found, for example, that the monkeys with genes rendering them more resilient, or less anxious (the longer strands), tend to be more willing to engage with others, to take risks, and to become leaders of the group. In other words, they show more confidence in their actions. His description of the complex social structure of the rhesus is fascinating and includes patterns of behavior that sound suspiciously like office politics. The leaders focus on alliances and occupy the best real estate; their corner office is a corncob case near