The Compassion Gene?

I teach a high school Sunday School class at my church, and recently we have been discussing topics raised in the book "Speaking of Faith" by Krista Tippett. In one of her chapters that discusses science and religion, she recounts several conversations she had with Lyndon Eaves, a professor of human genetics at Virginia Commonwealth University School of Medicine who also happens to be an Episcopal priest. I found this section of the book very interesting, as it raised a question I have asked myself over and over during the last six years of helping in China. Why do some people want to get involved to make a difference while others aren't bothered at all by those in need?

Mr. Eaves raises the point that through our mapping of a human's DNA, we can identify the genes for physical traits or for a person's IQ. But he asks the very interesting question of where are the genes that give us a passion for justice or the genes that cause someone to have a kind heart?

In my discussions with my class, I told them that most of us grow up hearing that people are the way they are either due to genetics or environment. After reading this part of the book, I began reflecting on the fact that we all know families who have 2-3 children who are loving and kind but then one child who just doesn't care about anyone else but himself or herself, and who even might be....well.....mean. Does that rule out the environment argument for a person being kind? I asked the high schoolers in my class where they think true compassion comes from. Can someone be taught to be compassionate? Do you think a desire to help others is part of a person's DNA and they either have it or they don't? Why do some people feel burdened to help those in need while others have no desire to ever get involved? What are your thoughts?