The problem with an essay like this is that it creates a dichotomy of good and mean. If a person is good or mean at one point in life, it doesnt mean that they

The problem with an essay like this is that it creates a dichotomy of good and mean. If a person is good or mean at one point in life, it doesnt mean that they were always that way or will always be that way. For example, as @mattmanser points out: Steve Jobs, Zuck, Bill Gates, Larry Ellison, Marcus Pincus, Uber, Kim Dotcom may all have done mean things in their lives but as @paul attests, at least some of them are actually good people. In conclusion, I think that the definition of "good person" and "mean person" are just too broad to make any sort of scientific conclusions.