Rodney Stark

High testosterone levels have been proven to make men more likely to commit crimes. The tendency in men toward risky behaviour keeps turning up even where socialization is different, and so does crime and delinquency.

In 1967, the world health community launched a global effort to eradicate smallpox. It took a coordinated, worldwide effort, required the commitment of every government, and cost $130 million dollars. By 1977, smallpox had disappeared.