You must have heard "A man is known by the company he keeps". Its also a universal saying "As you sow, so shall you reap". Man is a social animal, which means that man learns from his environment. No doubt inbuilt ability comes from the biological components we have, but it is nurtured only when its gets the proper opportunity from its surroundings.
I once read a Psychologists discovery about a child girl "Anna" at the age of 7 or 11 (if I am not wrong), this child was not able to communicate despite having all the biological abilities to do so. Why was it so? Because she was not exposed to the proper environment for her nurture.
Therefore the company we belong to has often a lasting effect on our nurture and habits which take along the full route of our lives.
Some people also would say that it is upto you to adopt anything and reject other behaviors you see in people of your company, but in the realm of actual life, it is very difficult to shape our thinking and behavior contrary to what we observe today. Take an example of immoral activites or sins, the more sinful company of friends you adopt, the more likely you are to be a sinner yourself. Its only rare that you criticize them and MOULD THEIR BEHAVIOR.