Definition from Matthew Weprin
“A common cause of inaction, in circumstances where action is obviously required (e.g. someone is crying out in distress and no one from a group of bystanders intervenes). In an ambiguous situation, people in a group check to see if others in the group are acting before personally taking action. Since everyone is checking, and no one is acting, the chance of someone acting becomes much smaller than if there is only one person present.”
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