Some economists have claimed that people are 95 percent selfish, that they are motivated almost exclusively by selfish motives. This did not ring true to the authors of this article. They hypothesized that human motivation is much more complex and nuanced. Specifically, they identified five distinct motives based on fundamental human needs. These motives are: own consumption, goodwill, promise keeper, belonging, and sharing. The authors then devised experiments to test their hypothesis. Their findings, summarized in this article, show that people are motivated by several interconnected factors and that these factors are weighted differently for different groups and in changing circumstances.