Why do we do it?

Like many people I engaged in helping others, not out of duty, nor a sense of responsibility, but simply because it was activity I wished to engage in. Determining factors included family and peer influence, academic studies, experiences, political leanings and a reaction to inequalities in our society and their causes. 

My exposure to the teaching attributed to Jesus was not the compelling determining influence. I did not need the prop of faith to influence or determine my actions. This is not to demean in any way those of faith who engage in good works as an imperative of their faith. However, in my opinion it is important that such engagement is not perceived as a duty, burden or chore, but as activity to engage in freely, willingly and with love.

What is it that motivates some to adhere to the concepts of human rights,  the Golden Rule and Love your Neighbour as integral to their lives and others to do the opposite?  Is it a consequence of physiology, social conditioning, experiences or a mixture of these factors?  Is it a deliberate choice logically arrived at?

More questions than answers.  Discussion on this topic welcomed.