Middle children have been called peacemakers, mediators, or simply overlooked. For decades, older siblings were described as responsible and younger ones as playful, while the child in between struggled to stand out. Yet new research suggests this underrated position has a surprising advantage: cooperation.

A new study led by psychologists Michael Ashton and Kibeom Lee gathered data from more than 700,000 people and found that middle children, on average, scored higher than their siblings on traits linked to collaboration. The researchers also discovered that larger families tend to produce children who value working together more than their peers in smaller households. Although these differences are relatively small, the massive data set offers compelling evidence that being in the middle can foster traits like agreeableness and humility.

A Surprising Edge for Middle Children

Middle children often grow up acting as a negotiator. The second-child “mediator” may help resolve squabbles between the older sibling, who commands attention through a strong personality, and the youngest, who leans on charm to escape trouble. Over time, the second child excels at smoothing ruffled feathers and keeping harmony in the house, an impulse that carries over into adulthood.

While this increased capacity for mediation can be a strength, many middle children also describe a lingering sense of feeling overshadowed. Some may attend therapy to address issues of neglect, pointing to how the oldest sibling often grabbed the spotlight while the youngest attracted extra indulgence. Experts note, however, that family environment and parenting styles play a crucial role in moderating these outcomes.

Birth order alone doesn’t dictate who we become. Other factors are at play: income level, parenting approaches, and the time period a child is raised shape development just as much as sibling rank. Still, these fresh findings highlight how living between an older and a younger sibling can build a unique skill set. Parents juggling the needs of multiple children often rely on middle kids to ease conflicts, and those abilities can flourish as the family grows.

Though some remain skeptical about the influence of birth order, the latest study brings renewed attention to middle children. They might not bask in as much parental spotlight as the oldest or steal as many hearts as the baby, but their knack for compromise and empathy can prove invaluable, both at home and beyond.