Pro-social behaviour and the bystander effect

What is pro-social behaviour?  Most of us have heard of anti-social behaviour.  This is behaviour that harms others and shows a lack of concern for their well-being.  pro-social behaviour is the opposite. It is behaviour that helps others and shows a concern for them.  Prosocial behaviour also includes altruism, which is when we help others and show a real concern for them, without any expectation of benefit for ourselves, and sometimes at a personal cost.  As a friend of mine ...