[This post comes with a massive disclaimer: I realize that the development of altruism is not a settled topic. Indeed, evolutionary psychology in general is a controversial field. But that's what makes it so interesting!]
I recently came across an NPR article entitled "Why Those Who Feel They Have Less Give More." The piece examines the social phenomenon that poor people tend to give more to charity, as a portion of their incomes, than their wealthy counterparts. However, wealthy people can be primed to act more charitably in situations where they are reminded of others' need.
NPR business journalist Paul Solman then dives deeper into the science of altruism in an interview with UC Berkeley psychologist Dacher Kelter:
Dacher Keltner: For a long time, I've been interested in a question that has confounded people who have thought about human evolution, and this goes back to Alfred Russel Wallace, Thomas Huxley and Charles Darwin, which is: Why in the world are people good to other people? Why are we kind? Why do we give things away? . . . What is it about the species we are that produces a lot of striking generosity in our social behavior?
Paul Solman: And your answer is...?
Dacher Keltner: My answer is hyper-vulnerable offspring that are born very dependent, taking years, decades to reach the age of viability. And that just changed everything. That meant we had to cooperate with each other; we had to share things.Keltner's use of the word "viability" caught my attention. Of course, he is not referring to viability in the 24-weeks-of-pregnancy sense. But I was struck by the idea that caring for non-viable children (that is, those who need help to survive) is the evolutionary basis for human altruism and compassion.
Contrast that to the pro-choice message: "You have no obligations to those who are not viable."
If we accept Keltner's theory, then the pro-choice philosophy stands in direct opposition to the way we as a species have learned to act selflessly. This is, essentially, the scientific version of Mother Teresa's observation that "any country that accepts abortion is not teaching the people to love, but to use violence to get what they want."
An aside: if Keltner is correct, and if we accept the data showing that low-income people are more inclined to be altruistic, then we might also expect low-income people to reject the pro-choice message regarding non-viable children and embrace the pro-life position. Sure enough, Gallup polling from 2011 shows that poverty is linked to pro-life views. This is especially true in the Democratic Party; Democrats earning less than $30K a year are a whopping 29 percentage points more pro-life than those making $75K or more. (In the GOP, which is more "unified" on the abortion issue, low-income Republicans are 2 percentage points more pro-life than wealthy Republicans.)