1. According to evolutionary theory, behaviors that optimize survival and reproduction are favored by natural selection and, therefore, more likely to persist. How, then, can we explain the evolution of altruism, which is by definition costly to the self? Provide an example.

2. Based on what you've learned about bystander intervention and diffusion of responsibility, what actions could you take to increase the likelihood that someone would help you in an emergency that happens in front of a large crowd? What obstacles to helping could persist?