Friends and families gradually grow more willing to create a happy life experience. Other shared moods, from exasperation to ecstasy, pervade the groups of closely involved people. Hopefully the mood of each new seeker of higher consciousness will be developed into a happy, constructive well being which is strong enough to easily shed destructive moods of others. Your companions very likely dominate, or at least greatly influence, your attitudes, too. The attitude of prejudice, for example, is still a major factor between neighbors and countries around the world.
Some groups form because of a shared prejudice.
Many times, for no direct reason, a member of a prejudiced group will find himself hating someone he doesn't even know, or trying to block the career of a person he has never met. The attitude of prejudice works two ways, of course. People in other groups are likely prejudiced against any such group in which you may find yourself. Self-righteous attitudes boomerang almost every time, often resulting in concussions and the letting of blood on the streets. Ideally, as you become more conscious, you'll refuse to let the attitudes of others dominate your own thoughts and feelings.