People are neither inherently good or bad. Given psychology and the structure of the brain, it's only due to ones own choices that label them. Therefore, one cannot "start their lives as a good person." Without a doubt, ones choices make them who they are, and these choices and/or actions are the only things that can label a person "good or bad." You see, you can't simply be good with a "layer" of evil around yourself (if that makes sense). Final ruling: When one begins life, they are neither good or bad, and it is their actions that make them who they are.