Groups can draw on more resources than a lone individual. Groups can also generate more ideas and possible solutions by discussing the problem. Groups can also pressure individual members to accept the solution, even if they have doubts. People generally feel that a group's decision will be superior to an individual's decisions. Groups, however, don't always make good decisions.
Juries sometimes render verdicts that run counter to the evidence presented.
Community groups take radical stances on issues before thinking through all the ramifications. Groups can stumble, but groups that make disastrous decisions require special explanation. Groupthink, which was coined by Irving Janis in his classic book Victims of Groupthink, is considered a disease that infects healthy groups, rendering them inefficient, unproductive, and irrational. Janis has identified a number of causes of groupthink, and many were likely operating in the Heaven's Gate group. Groupthink only occurs in cohesive groups.