One of the simplest, most illuminating books I've ever read is Arnold Kling's The Three Languages of Politics.
Kling's idea: conservatives, liberals and libertarians communicate (more on whether it's just communicate or something else later) about political issues on three, separate axes:
Once you notice this framework, it becomes a lot easier to understand other's views on almost any issue.
Many issues span all three axes. Illegal immigration is typical example.
Progressives view immigrants as oppressed by unjust immigration laws, border patrol agents, ICE, etc. They're more likely to pay attention to kids in cages or stories about fully assimilated DREAMERs excelling in school at risk of being deported.
Conservatives argue that immigrants (particularly illegal, but legal too) have negative cultural impacts on "civilization" (western, market oriented, traditional values) at the margin.
They also tend to focus on the fact that (by definition) illegal immigration is against the law. They talk a lot about rates of criminality by immigrants, and pay attention to anecdotes about immigrants advocating things like Sharia law.
Libertarians believe people should have the freedom to live, work and enter whatever mutually beneficial economic arrangements they want. They are against immigration laws that prohibit this.
They'd pay more attention to stories of hardworking immigrations who came up from nothing (conservatives also appreciate this narrative) who are driving a taxi to earn money to send back to their families.
Other examples of issues that pretty clearly span all three axes (see if you can mentally make the argument for each axis):
(The last two come directly from Kling's book).
If I were a middle or high school social studies teacher, I'd make students analyze issues in terms of the axes all day long.
Many issues have three distinct axes based arguments. But often a fight about an issue will be between two of the three camps. Take California Proposition 22, which is about whether Uber and Lyft should be able to classify their drivers as independent contractors instead of employees.
Progressives argue classifying drivers as contractors is a way for ride sharing companies to exploit drivers. They think Uber is oppressing drivers by not paying mandated employee benefits (overtime, paid sick time, health care, etc).
Libertarians argue out the rideshare-driver relationship is between the companies and their drivers. No one is forced to drive for Uber. If someone needs healthcare, paid sick leave, etc, they're welcome to find a job that offers it. If enough people feel similarly, to the point Uber was having trouble attracting drivers, they'd change their business model.
This particular fight doesn't seem to fit the conservative axis all that well.
On some issues, a dominant axis may emerge, where most people find themselves on a certain axis, even if they don't usually frame issues this way.
For example, most people today view 1960s civil rights struggle in US on the oppressor-oppressed dimension. This clearly wasn't the case at the time; many people then thought individual businesses and people should have the freedom to discriminate if they want.
While some people still believe this, they're pretty hardcore on the freedom-coercion axis. Most people in US today view the issue through the oppressed-oppressor lens, and take a favorable view of civil rights.
Other examples: initially, I think most people viewed both 9/11 and the Charlie Hebdo shootings in civilization-barbarism terms (though apparently many on the left have recently been accusing Charlie Hebdo of racism, so maybe not).
Having though about the three axis model for a while and gotten in the habit of viewing contentious issues through the various lenses, here are some miscellaneous thoughts and open questions.
Each axis has its good end, i.e. freedom, civilization, non-oppression (OK, it's debatable whether the progressive axis has a "good" end or whether they're just anti-oppression).
It seems like thinking primarily on an axis means you tend to discount whether the good ends of the other axes are worth pursuing. I think helps explain certain behavior, and makes the model even more useful.
For example, conservatives care about civilization. Do progressives and libertarians?
Progressives and civilization. I think anti-civilization feelings on the left are most associated with the environmental movement. You can also see it in tendencies to romanticize pre-colonial, indigenous societies.
Libertarians and civilization. I would say libertarians appreciate civilization more than progressives, but not as much as conservatives. Example: many libertarians advocate open borders on principle, even if it might put some of the freedom/market aspects of western culture at risk.
Libertarians care about freedom. Do progressives and conservatives?
Progressives and freedom. There is obvious, historical evidence that progressives don't value freedom that highly. But even today, at the margin — are progressives in favor of individuals being free to spend their money on (or hire, or eat, or wear) what they want, or less?
Conservatives and freedom. Again, conservatives probably care more about freedom than than progressives, but they're definitely willing to make it take a back seat if they think other things are more important. See the NSA, Patriot Act, Snowden, drug war, historical opposition to gay marriage, etc.
Progressives care about stopping oppression. What about conservatives and libertarians?
Conservatives and oppression. While very few people think of themselves as pro-oppression, I think many non-progressives take issue with much that is categorized as oppression today. For example, conservatives point out that when you control for violent crime rates, it doesn't appear minorities are systematically more likely to be shot by police than whites.
Libertarians and oppression. I think libertarians would generally agree (though on this issue, many would also say police are too militarized and powerful). They also have more of a freedom bent, and are hesitant to call anything the result of voluntary transactions oppression. "Yeah, working in a sweat shop would suck, but these workers technically have a choice".
While we're on the subject of police shootings, an aside: the dueling progressive-conservative slogans, "black lives matter" vs police as the "thin blue line" that protect us from anarchy are straight out of the three axes model.
Kling is careful to say he's talking about communicating about political issues. That's why the book is called the three languages of politics.
"Let me quickly add that I do not believe that the three-axes model serves to explain or describe the different political ideologies. I am not trying to say that political beliefs are caused by one's choice of axis. Nor am I saying that people think exclusively in terms of their preferred axis.
I'm not sure that goes far enough, though it's obviously noisy. But I would expect, for example, that people who identify with the freedom-coercion axis generally favor smaller government, fewer regulations etc.
Also, given the way most people's internal monologue, language as thinking brains work, the difference between language and thinking isn't necessarily clear.
In a follow up edition, Kling toyed with adding what he called a bobo/anti bobo axis.
Bobo is an idea from the NYT columnist David Brooks 2000 book Bobos in Paradise, which (in my understanding, I've never read the it) is basically the cosmopolitan/elite/smug/"believe science" vs the backlash/anti-smug/troll/"the CDC originally said not to wear masks" axis.
In particular, the phenomena of Trump, who — while he definitely has conservative themes like law and order, isn't exactly the epitome of western civilization — makes this axis intriguing.
Here I'm mostly thinking of progressives, which seems to have taken the oppression/non-oppression axis so far in one direction (particularly when it comes to racial, sexual and gender identities) that it always reminds me (not sure if this is weird) of allergies.
Allergies are caused by your body's immune system reacting too strongly to things that are really not that big of a deal. Similarly, the left's hyper sensitivity to any sort of (real or perceived) identity-based oppression is causing real dysfunction, both within the left itself and in society at large.
My guess: this is mostly relevant in impacting how people view the extent of oppression.
Take the underrepresentation of women in tech. If everyone is a Blank Slate, the fact there are fewer women in tech might be due to oppression.
But if — on average (individuals are all over the place, which is good!) — women are naturally less inclined to study tech related fields (whether because of a things/people dynamic or because on average girls are better at reading, whatever) than this disparity might be just something that happens, no oppression necessary.
Note: even if true, this doesn't at all mean women can't like tech or are "weird" (or less feminine) if they do, any more than men who like to read. Again, differences within groups swamp differences between groups. It also doesn't preclude oppression.
Caplan's theory: the left hates markets, the right hates the left.
While possibly tongue in cheek, these models do attempt to explain similar things.
Are certain groups (OK, conservatives) more inclined towards conspiracy theories? If so, why?
When you stare at them for a while, the boundaries between axes gets a bit fuzzy.
So, question: to the extent there is overlap, what should we do about it?
Answer: probably just not think about it too hard. It's a model, not necessarily exactly the way the world works in granular detail.
E.g. see the GOP House Freedom Caucus, which starting in 2016 did a massive shift away from Freedom/towards Trumpism. To the extent this sort of thing happens (both at the individual and group level), the model seems less useful.