So says a new study.
A study of 10,000 US students over a period of 35 years suggests the wealthiest people are those that had the most friends at school. Each extra schoolfriend added 2% to the salary.The researchers said this was because the workplace is a social setting and those with the best social skills prosper in management and teamwork.
Friendships help us develop as people, says Mark Vernon, author of The Philosophy of Friendship, but the very term "friend" covers a whole range of relationships. You have a very close friendship with your partner but with others it may just be a common interest or history or simply children the same age.
The average number of friends is about 150, says leading anthropologist Robin Dunbar.
"It's the number of people that you know as persons and you know how they fit into your social world and they know how you fit into theirs. They are a group of people to which you have an obligation of friendship."
They usually consist of an inner circle of five "core" people and an additional layer of 10, he says. That makes 15 people - some will probably be family members - who are your central group and then outside that, there's another 35 in the next circle and another 100 on the outside. And that's one person's social world.