Her neighbor could not afford to repair the roof on her house,so Tijuana secretly hired and paid for a contractor to repair the roof.The neighbor never knew who was responsible.Tijuana's actions are an example of

A) altruism.
B) social exchange.
C) equity.
D) the reciprocity norm.

Tijuana's actions were selfless and aimed at helping her neighbor without any expectation of getting something in return. This fits the definition of altruism, which means helping others without any self-interest. Social exchange and equity both involve some sort of exchange or balance of benefits/rewards, whereas the reciprocity norm refers to the expectation that people will help those who have helped them in the past. None of these concepts fully capture Tijuana's actions in this scenario.