Social psychologists study the circumstances in which people offer help to others.
Research shows that people are less likely to offer help to someone in distress if other people are also present. This is called the bystander effect. The probability that a person will receive help decreases as the number of people present increases.
Diffusion of responsibility contributes to the bystander effect. A person does not feel as responsible for helping someone if several others are also present, since responsibility is distributed among all those present.
Researchers have proposed that bystanders who witness an emergency will help only if three conditions are met:
Researchers suggest that people are most likely to help others in certain circumstances:
Some social psychologists use the social exchange theory to explain why people help others. They argue that people help each other because they want to gain as much as possible while losing as little as possible. The social responsibility norm also explains helping behavior. The social responsibility norm is a societal rule that tells people they should help others who need help even if doing so is costly.
Another norm that explains helping behavior is the reciprocity norm, which is the implicit societal rule that says people must help those who have helped them.