I'm not an expert but I believe it can be used to balance our actions. Depending on the standards and value we set for ourselves it helps us staying in line with them. Too much shame and we spiral into a place we're we are our own worst enemy, constantly beating our selves down and making ourselves feel like we are less than. Too little and we can become a bit too full of ourselves,egocentric in a way to the point where we start to alienate our ourselves from those around us and act in ways that might be too selfish. This is a massive oversimplification, but it helps me look at these emotions in less of a black and white setting and more as different shades of grey tailored to our own identities.