There were some differences between the people who helped and those who didn't help, however. After decades of applying rigorous scientific methods to this investigation, psychologists now know that many factors are related to the failure to help someone in need. One example is egoism, which is exclusive concern with one's own welfare. Still other factors are related to the situation. Potential helpers also must weigh the costs of intervening.
Scientific evidence suggests otherwise.
Psychologists know that the question of bystander intervention is a complex one, involving the interplay of many factors. A law could not eliminate all the myriad factors that are critical in making the decision to help. Research indicates that there is a need to attack the problem from many directions. We can do this in our schools, and through our media. As a society, we need to create a social norm that encourages altruism.