Jonathan Haidt provides, perhaps, more nuance, arguing
there are (at least) six innate moral foundations, upon which cultures develop their various moralities, just as there are five innate taste receptors on the tongue, which cultures have used to create many different cuisines. The six are Care/harm, Fairness (equality)/cheating, Liberty/oppression, Loyalty/betrayal, Authority/subversion, and Sanctity/degradation. The theory was developed to explain cross-cultural differences in morality, but Haidt and his collaborators at YourMorals.org[21] have found that the theory works well to explain political differences as well. Liberals (leftists) tend to endorse primarily the Care and Equality foundations, whereas conservatives (rightists) tend to endorse all six foundations more equally.
What I would suggest is that while both writers have solid points in my view, what they are REALLY referring to is what sorts of propaganda both groups respond best to.
One can be empathic and care about others, and be led to support policies which actually work to achieve the opposite of the outcome you wanted. This is the case with most Democrats.
One can be callous and cruel, seeking ones own interest, and in the process of building up a large company–say, Microsoft–in actual fact enrich the lives of millions of people.
What I can say with some firmness is that the Left chooses to focus on the discussion, and conservatives–to the extent we actually exist any more, having been largely pushed in fact if not name from the national and international stages–choose to look at history, and particularly political and economic history, as models to predict the future. And we are rarely wrong. Human nature has not changed since the time of the Romans and Greeks. Nor is it likely to any time soon.
Simply because someone says they want something, does not mean that their means are not counter-productive. And if you criticize people who oppose those means as inherently mean-spirited and evil, then you have eradicated the capacity of that system to learn, adapt, and grow, which is where we are at today. All of our problems have solutions, but none of the problems can be named, and thus all of the solutions look abusive and wrong.
The goal of free markets and the protection of property rights is generalized wealth and well being. But because it LOOKS like self seeking and greed, stupid people can, have, and continue to misunderstand this, even though the data is absolutely, categorically clear, beyond any possibility of rational dispute.
An appeal to prejudice is inherently an appeal to ignorance. There is no other way to look at it, in my view.