* Kin selection: This theory proposes that humans are altruistic toward their relatives because it increases the chances that their own genes will be passed on to future generations.
* Reciprocal altruism: This theory proposes that humans are altruistic toward others in order to gain something in return, either directly or indirectly. For example, someone might help a stranger in need in the hope that the stranger will return the favor in the future.
* Empathy: This theory proposes that humans are altruistic because they are able to understand and share the feelings of others. When someone sees someone else in need, they may feel empathy and be motivated to help.
* Social norms: This theory proposes that humans are altruistic because it is expected of them by their society. For example, in some cultures, it is considered to be rude or selfish not to help someone in need.
It is likely that all of these theories play a role in human altruism. The relative importance of each theory may vary depending on the individual and the situation.
