I believe I understand what you mean now, although it's possible we might be conflating the environment having a large impact on ones behaviour (which I agree you are correct on), and; someone's innate personality developed due to genetics and their collected experiences in different environments and as such behaving better, worse, or different in those environments. Essentially we are arguing Nurture vs Nature, or Environment vs Genetics, right? I believe they both have a large impact and can cancel each other out.

For instance in your first example, a very charismatic person might not get a reputation for being a dickhead because everyone loves him due to his loveable personality, yet he's in the same environment and situation as the person who is known as a dickhead.

> I can give you a much simpler example. Put 10 people in an arena and give them a sword, gladiator style. The last standing gets to stay alive.

> Congratulations, you just discovered that any human can be turned into a murderer in 10 minutes! They adapted to their environment.

Have you ever been in a disaster or life threatening situation? There's a fight or flight response and that response can be different depending what sort of personality you have, right? I imagine not everyone would fight in your hyperbolic example if we simulated it thousands of times. I guarantee there are many people out there that would drop to the ground crying in a ball rather than fight to the death.