There are a lot of studies that show correlations between different parts of ourselves and the effects that it could have on the world. People that are extraverted are more likely to spend above their means, people with lower self-control are more likely to be overweight, people with higher intelligence are more likely to be successful, people with higher memories are more likely to be prodigies and so on.
But there are some things are are a lot easier to improve and some things that are a lot harder to improve. According to my psychological teacher, a person can not train intelligence and cognitive flexibility, but they can train self-control, which still effects among other things also success in school and marriage stability.
From this we can at least agree, that some things, like some parts of intelligence are a lot harder to improve than self-control.
Then we have the whole mentality to take into account as well. People that believe that they can improve are more likely to improve compared to people that believe that genes decided their faith. I have seen these things in a different contexts as well. One example is, that people that believed that their self-control was limited and can tire like a muscle, were more likely to have limited self-control than people without this belief.
It is like whatever we believe in it becomes true.
But our beliefs, unlike what some NLP (as in neuro-lingustic programming) practitioners would like you to belief, are not so easily changeable. There is a reason why people say that we become the average of 5 people that we spend the most time with. Any kind of input, even implicit and never mentioned like the cultural setting, can influence our beliefs.
Taking this into account I can see two possible ways. One is to simply reshape the whole world around you so that there are only influences going in the right direction. That means not talking to people holding different opinion, no reading the newspapers, no watching of the TV shows, no reading books and so on, since all these things could influence it in a different direction.
It entails an extreme level of curtailing the influences on one person. I takes a lot of work, but if you are willing to do it and pay the price, it is a valid path.
The other one is to simply use the strategies that work in this world. If most people believe that intelligence can't be improved, but self-control can, then work on your self-control. This way even the environment that is not fully compliant with you goals or aims can still help with taking steps.
I am sure that there are overlap in the world and human's growth path, especially when the person is starting on the similar level to most people. I believe that taking advantage of the world in the beginning is the quickest path.
Eventually, the overlap does get smaller and smaller, and the person will need to switch more to a upper strategy, until the the environment will change enough that there is still overlap. It is like a cycle strategy, switching between the both methods.
Does this mean that I think the same world can have different influence on us? Yes, I believe this. And I think it makes sense to take advantage of this.