The Q&A: Steven Pinker: The violent dangers of ideology | The Economist

http://www.economist.com/blogs/prospero/2011/11/qa-steven-pinker-0
Consciousness is increasingly seen as the origin of moral worth.
Empirically, the huge increase in abortions has not accompanied an
increase in the neglect or abuse of children. A common prediction in
the 1970s before Roe v Wade (a landmark decision by the United States
Supreme Court on the issue of abortion) is that abortion would
inevitably lead to legalised infanticide. We can say with confidence
that that prediction was incorrect, which supports the idea that
people's intuition doesn't equate abortion with murder, that legalised
abortion did not place people on a slippery slope. The slope actually
has a fair amount of traction and I think what gives it traction is
the equation of moral values with consciousness

---SPSmith