Team Genius

“Dunbar’s Numbers”

Biological hardwiring makes people want to form teams. Early humans banded together to hunt. Humans don’t function as well alone; they thrive in pairs or groups. Just as molecules form bonds – some of which are more stable than others – so do human beings. Pairs are the simplest and most stable bond in chemistry and in life. Humans form “pairs” in love and marriage and as friends. Adding a third person to a pair often complicates matters, and some “trios” can be explosive. Members of successful trios have different skills and balance each other.

Experts debate the optimal size of teams larger than three. British anthropologist Robin Dunbar found that a team of five to nine (“7±2”) sits at the upper limit of the number of people with whom someone is truly close, like family. A team of 11 to 18 people (“15±3”) is at the top limit of people someone can truly trust. Dunbar found that 150 people – “the Dunbar number” – is the maximum effective number of people with whom any person can share a personal, social relationship. “The 150 team is the most famous Dunbar number – and as such, it may be the most stable human grouping.” Another common “magic number...