We are shaped by the people who surround us. Our joys are more pleasurable when they are cherished by our friends, our successes more enjoyable when they are applauded by those whose opinions we care about, our protests are less lonely and our indignation less unsure when shared by our supporters, our hatreds more corrosive when goaded by fellow zealots, our sorrows less burdensome when borne with our family.
Moreover, we gauge our actions based on how they affect people near us, on the indentations our actions make on their lives. Without such effects, we would be ephemeral passersby, with little evidence of ever having existed. Each one of us draws from multiple overlapping communities that help define who we are, that give us identity over and above the core we think is uniquely us.