17. We sometimes assume other people will help so we don't have to
Mattias Wideklint says he's intrigued by the "bystander effect," which occurs when the presence of others discourages an individual from intervening in an emergency.
Psychologists Bibb Latané and John M. Darley became interested in the phenomenon after the murder of Kitty Genovese in 1964 — supposedly, many people heard Genovese screaming, but failed to act.
In Latané and Darley's experiment, researchers measured how long participants would stay in a room filling with smoke. Some participants were alone in a room; others were accompanied by two or three passive confederates. Results showed that participants left alone were significantly more likely to report the smoke.
However, a more recent meta-analysis suggests that the bystander effect is less pronounced in highly dangerous situations, meaning that people in groups are more likely to help if they think someone's life is really in danger.
And in the last few years, the story of Genovese's murder has been revised. There may not in fact have been dozens of passive witnesses and it's possible that no one saw the final assault, suggesting that the bystander effect may be more nuanced than we once believed.