text: Some activities put you into a social environment. Being social is a key part to being healthy; It can both cause and relieve stress. On a team, all the teammates work together creating bonds between themselves, boosting confidence. To build confidence you need to be proud of what you do, and friends and teammates can help build that with you. Being able to talk to someone is also a needed skill, and coordinating with teammates can form that skill. Working on a team where no one plans with each other, doesn't help much with social life.