“Part of our primate heritage is that most of us want to feel that we fit in somewhere and are part of a group. Which group we're part of may matter less to some of us than others, as long as we're part of a group and not left entirely on our own. Although there are individual differences, being alone for too long causes neuro-chemical changes that can result in hallucinations, depression, suicidal thoughts, violent behaviors, and even psychosis. Social isolation is also a risk factor for cardiac arrest and death, even more so than smoking.” GroupsPrimate Heritage Author:Daniel J. Levitin