People want to work with people. Most of the hermits out there got hurt along the way and have decided that it’s easier to avoid others than risk being a part of a dysfunctional group. Show the hesitant recruit the best part of the team and they will join just to be a part of the fun group that seems to genuinely like being around each other. Hesitant people need to see that their past experience isn’t the norm. People can enjoy working with others in a trusting and fun dynamic. The recruit needs to know what they will miss out on if they pass on joining the team.