The interesting thing (to a non-conservative, non-progressive like myself) about conservatives and progressives, is that most of us can intuit whether someone is one or the other, without being able to clearly state what rule(s) we use for knowing. It's not like being authoritarian or libertarian, where there's a clear question (more authority, or more liberty?) that you can answer to know the difference. Conservatives, despite their label, sometimes want radical change, and progressives sometimes cling to existing (or obsolete) institutions, so it's not as simple as who wants change and who doesn't. It's also not as simple as who likes poor people and who doesn't, as progressives have often ruefully observed that they have a problem getting lower-income and especially lower-middle income voters to support them in elections. But, if the difference is so hard to determine, how is it that we almost all are able to do so successfully, almost all the time? It's rather like native speakers knowing the rules of grammar for their own language; even if they can't explain what those rules are to someone trying to learn it, they know when it sounds wrong. The rule is learned, but hard to state.
One difference I've noticed, is that conservatives dislike questions, and progressives dislike answers. If the results of scientific research throw doubt on long-held beliefs such as the authority of the Bible on questions of the age of the universe or the origin of humanity, it is conservatives who dislike it. On the other hand, if scientists find a way to measure, quantitatively, something like IQ, it is often progressives who are most uncomfortable about that. It is not simply that they don't like the result (whatever it is), but rather that the very act of answering a question like "what is the average IQ difference between genders/races/nations/classes" is one which progressives don't want to see answered.
Another way of putting this, is that progressives are more comfortable with uncertainty than conservatives. Note how this says more or less the same thing as "progressives are less comfortable with certainty than conservatives", but which way you state it changes how it sounds, with the first way sounding like a compliment of progressives relative to conservatives, and the second sound like the opposite.
There's another, I think related, difference between the two mindsets. The ethic of progressives seems to be essentially, "there is money available to solve our problems, so who has it and isn't sharing?" The ethic of conservatives is more based on the idea of, "there is not enough money available for everything, what needs to be cut?" Progressives have the ethic of plenty, and conservatives have the ethic of scarcity.
This leads to a difference between the two groups in their attitude towards compassion (or its flipside, hard-heartedness). Progressives value compassion greatly, probably because it is almost a prerequisite for sharing. Conservatives, on the other hand, seem to value hard-heartedness, seeing it as a necessary trait for making difficult decisions sooner rather than later. If you think that compassion will only delay the inevitable, and make things worse (because in most cases, delaying cuts only throws good money after bad, making the eventual situation worse), then it makes sense that you would value hard-heartedness and regard compassion as morally suspect.
The vast majority of both conservatives and progressives eat meat. Which group is more comfortable with the idea of hunting? It is not a question of animal rights, since most people on both sides are ok with the idea of an animal being killed and eaten, in the abstract. But in order to kill an animal, you have to be willing to face the emotional reality that for some to eat, others must die. Conservatives tend to be able to do this. Progressives tend not to be as good at this particular kind of decision.
Let us say a person comes upon an animal by the side of the road, which has been hit by a car. It is clearly in great pain, and probably too badly hurt to survive, but it is not dead yet, and may suffer through several minutes of agony if nothing is done. Let us further say that the person who finds that animal, is not able to bring themselves to shoot it and put it out of its misery. What would a typical conservative think of such a person? What about a typical progressive? Notice how you can guess at the typical reaction of conservatives and progressives to this situation, even though it is not really a question of politics.
The mirror image of this question, is to imagine that a person found such an animal by the side of the road, hurt but perhaps saveable if it were taken to a vet promptly. If the person determined that they had other obligations which were more pressing, and left the animal to its fate, what would be the difference in attitudes towards such a person, among conservatives vs. progressives?
The ethics of plenty or scarcity also relate to expectations about the future. If you think that any scarcity that exists is temporary, then taking on debt to remedy that is sensible, and the interest which may be required in the future is not seen as much of a problem. If you think that scarcity is a fact of reality, in the future no less than now, then the sooner cuts are made, the better.
Debt is therefore viewed differently depending on whether it is viewed through the ethic of scarcity or the ethic of plenty. If you believe that resources are truly scarce, then debt is just a way of putting off the cuts that must come eventually (and making them worse, since interest payments are incurred). On the other hand, if you believe that the real problem is not a lack of resources, but a lack of compassion to share them, then debt is a useful way of putting off unnecessary cuts until the time when those who have, can be made to share.
Why is it, then, that progressives have so much trouble getting the lower middle class to support them? Why is it that economic hard times tend not to result in a swing towards progressives, even though progressives are typically more willing to spend government money on support for those in dire economic straits?
To make sure our thought experiments here are salted with a little data, we can look at the research of Andrew Gelman et al, which has helped us to understand the apparent paradox that poor states tend to vote Republican. It is not that those with low income are more likely to vote Republican. The reality is the reverse, in every state, although also in every state there are both Democratic and Republican voters in every income bracket. However, even after accounting for differences in race, gender, age, and education, it appears that the difference between the voting preferences of low and high income voters is greater in poor states than in rich ones. In other words, in rich states, voters in higher income brackets are more willing to vote Democratic. In poor states, the impact of income on voter preference is greater, and especially in making upper income voters more likely to vote Republican.
Viewed through the lens of the "ethic of scarcity" vs. the "ethic of plenty", these results make sense. If you live in a poor state, you are more likely to perceive a scarcity of resources, regardless of whether you in particular have enough. If you worry that you in particular might be the one who gets thrown overboard, you may nonetheless lean progressive, but most voters (and especially those of above median income) will value the conservatives' ability to make hard choices and suppress empathy.
On the other hand, if you live in a rich state, you are more likely to believe in the "ethic of plenty", and see the problem as a lack of caring, not a lack of resources. Even if you are confident that any culling of the weak (/poor/lower skilled/etc.) will not fall on you, the solution to the problems of society will appear to be sharing more, not cutting more.
Any theory of this sort needs to be put to the test with some testable predictions. Here are a few.
To be clear, I don't have the datasets available to test any of these three predictions (yet, anyway); they are testable predictions, not statements of fact. Anyone who knows of a publicly available dataset that could be used to test any of the three, is invited to contact me.