Why we doubt people around us?

First of all, I don't believe in any kind of "golden era" of humanity. Human nature has not changed over our thousands of years of societies. Societies come and go, they have golden and dark ages. There is no great past to aspire to. Looking backward doesn't help. Looking forward is all we can do. One thing's for sure, giving up and giving in to cynicism doesn't help either. It can be hard to find trust in a society that seems to be getting more anonymous. If we could just put ourselves in someone else's shoes more often, I think it would solve a lot of societal problems. If we could stop seeing people who are different from us as "the other", it might be easier to trust them.