That's a pretty heavy question that's taken people lifetimes to explore. :)

I think long and short of it though, is that it's important for us to not lose faith in ourselves as individuals, to not lose faith in eachother as individuals, and to realize that changes of heart can come from the most unexpected of places and at the most unexpected of times. Because these changes of heart can be unexpected, can be positive or negative, and often seem to come at times when we're most vulnerable to the world around us, it's important to try to create an environment whenever possible that allows for positive changes and developments to take root.

That said, it's still important to be guarded about who we trust and why, when and how we trust them, etc. Sometimes people make mistakes, which is unfortunate. Sometimes people act with ill will and malice, which is regrettable. By making good and healthy decisions about how we conduct ourselves around others and how we allow others to conduct themselves around us, we can go far in protecting ourselves, them, and society as a whole.

Personally, I think the same philosophy applies to institutions, whether we're talking about families, schools, corporations, governments, or what have you. The scale might be different, in degrees of severity, time, etc., but I think much of the same mechanisms are there, as these institutions are a collective extension of our own individual humanities.

Edit: Dala once played an amazing podcast about how over a long stretch of time people's brains literally change. It was all in the context of actual criminals and was very compelling. I'll have to see if I can't find the episode and share it with Hubski.