Flynn has speculated, and I agree, that abstract reasoning can even hone the moral sense. The cognitive act of extricating oneself from the particulars of one’s life and pondering “There but for fortune go I” or “What would the world be like if everyone did this?” can be a gateway to compassion and ethics.
And yet there are smart people who are real scumbags. And I'm sure Dr. Pinker would answer by the difference between individual examples and overall trends.