Free Invisible Influence by Jonah Berger

played with, her teammates nicknamed her “Plankton.”
    But her size, and skills, soon grew. She played before and after practice, drilling fundamentals with whomever she could find. Chest traps and volleys. Touches with each side of each foot. Repeating the same simple movements again and again until they became second nature.
    A year after her failure, Brian made the state team. Then the regional team. And eventually the youth national team. A decade later, she stepped on the field as the youngest member of the U.S. national team. At twenty-two years old, she was one of the linchpins that helped the team win the 2015 Women’s World Cup.
    A prolific scoring midfielder, Brian has been called the glue that connects the defense to the offense. Some consider her the future of U.S. soccer. America’s next big star. A new Mia Hamm in the waiting.
    But the first opponent Brian faced wasn’t a crafty Brazilian forward or a hardy German defender, it was her older sister, Jennifer. Together they would kick the ball around their parents’ front yard until it was time to come in for dinner. Jennifer was five years older, so Morgan didn’t win many one-on-one games, but it fueled her interest in the sport.
    It turns out that Brian’s not the only one. Elite women’s soccer players tend not to be firstborn children. Of the twenty-three players on America’s 2015 Women’s World Cup team, for example, seventeen have older siblings.
    Coincidence?
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    Like any organization, the U.S. national team is interested in predicting which players will do well. What makes some perform better than others? Do certain factors tend to be associated with success?
    From the national team itself to the feeder groups that start as young as middle school, slots are limited. There are only so many players that make the cut. But it’s tough to pick and choose. How should they pick who to invite and what predicts whether someone will be a national team player someday?
    To find out, researchers studied players of all ages. 1 Girls that participated in at least one U.S. women’s national team training camp, from the under-fourteen level all the way up to age twenty-three. They measured a variety of factors, from physical capabilities and psychological profile to geography and aspirations.
    There were all sorts of intriguing relationships. Successful players tended to live with both parents, their mothers or fathers often volunteered to help the team in some capacity, and their parents often had received post-secondary education.
    But beyond all these aspects, one factor stuck out: birth order. Three-fourths of the best players in the country have at least one older brother or sister.
    And it’s not just soccer. Examination of more than thirty sports across the world found the same pattern. Top athletes tended to be later-born children. 2
    There are many reasons that having an older sibling might make someone better at sports. Watching an older brother or sister provides an early introduction. Older siblings can teach their younger counterparts how to play and serve as inspiration.
    Older siblings can also serve as training partners or competitors. It’s not called sibling rivalry for nothing. Competing against older, often bigger family members forces younger siblings to develop quickly. They have to cope with being smaller, lighter, and often slower. To keep up with, or even beat, their older siblings, younger siblings have no choice but to learn fast. Thisnatural “playing-up” environment motivates them to take more risks and build their skills.
    Interestingly, though, while elite athletes tend to have older siblings, those siblings didn’t necessarily play the same sport. These older brothers and sisters were generally active and involved in some sport, just not necessarily the sport at which their younger siblings ended up being successful. Elite soccer players, for example, had older