I'm sure there's a real term for what I'm trying to describe. I've found our opinions and values change slowly, over time as we interact and take on new experiences. We think we're more fixed than we really are. Often, that's a good thing - "When the facts change I change my mind what do you do Sir". But, in the same way that only seeing news of one political kilter can subtly reinforce our views, interacting with people who have one set of values has the same impact. Professions tend to filter for values that people care about and that reduces the 'diverse social sphere', it's the real-life version of Facebook filtering news feeds!
Perhaps I should add I'm thinking "in the long term", so comparing working directly in a charity for 10 years versus working as a trader and giving a high percentage of earnings to charity.