Why do people instinctively reject group activities?

Because of their strong personalities, they are self-centered and always feel that others are hypocritical, and they are even more reluctant to socialize with those they don't like, always giving a cold response. I feel that I would rather be recognized as 'noble' by others than to be in the company of a bunch of hypocritical mortals, let alone have an interest in socializing. Doesn't take an active interest in others, but makes you feel like he's always around; doesn't overdo the pleasantries, but usually doesn't say no when you need him; doesn't express how important you are, but you can see the importance of it in his actions. Because of this it is more excluded from group activities.