Left-wing Alarmism vs. Right-wing Optimism: evidence on which is correct?

Of course, it's not all that clear cut. More likely, there is a spectrum between those two extremes.

Examination of this sentence should set alarm bells ringing. The world is wide and things (and people) can vary in many ways. To just focus on a skinny line in this wide world is to throw away almost all of your information.

Noam Chomsky will tell you that violence is increasing for a while, by showing "structural" violence like poverty, starvation

Under what meaningful time frame could he claim this to be true? When has the world every been wealthier and less violent?

I've noticed two meme clusters, which one is correct?

If each meme cluster proceeds in a commonly understood way from a single disputed issue, then calling it a "cluster" is misleading. Ask yourself which side of the disputed issue is correct.

If instead they really are clusters of N orthogonal memes, the fact that you see 2 clusters instead of 2^N clusters is evidence that neither group is entirely correct; clearly groupthink is causing people to overvalue partisan arguments and self-segregate into semi-arbitrary groups.

The internet is the Land of Self-Segregated Semi-Arbitrary Groups, by the way, and LessWrong is afraid of being drowned in partisan groupthink and going down the same path. Downvoted for adding to that risk. "How optimistic or pessimistic should we be about the future, and why?" could have been asked in a less politically trollish way.

Our minds are spectacularly good at generating simple ways to categorize political debates- it's almost as if that's what our intelligence originally evolved to do. Just because this dichotomy feels like an epiphany to you doesn't mean it's there.

Nor does my skepticism mean it's not a real thing. But the point is, you can't get anywhere with armchair reasoning about the political discourse- there are just too many ways to slice it. If you really think this is worth investigating, look for patterns in the General Social Survey.

Now, I'm especially puzzled by the correlation between political sides what seems to be the Enlightenment/Romanticism divide.

I'm not sure I see the correlation. On the one hand, some right-wingers do support deregulation and believe that the market will sort things out, while some left-wingers believe that urgent action is needed to avoid collapse[1]. This would suggest that right-wing is Enlightenment and left-wing is Romanticism. On other issues, especially social or moral issues[2], leftists believe that new technologies will be a force for good and should be freely available, while rightists believe they are a threat to ("traditional") morals and should be curtailed. That would suggest that the right is Romanticism and the left is Enlightenment. I suspect the reason for this apparent divide is that the parties and their constituencies are choosing their positions based on pro-business, pro-religion, or pro-intellectuals'-signalling-based-opinions, rather than by adherence to consistent Enlightenment or Romantic ideas.

[1]: To be specific: financial markets, oil drilling, farming practices are issues where this pattern appears most visibly.

[2]: Specifically: euthanasia/right-to-die, stem cell research, genetic engineering of crops or people.

Downvoted for politics, false dichotomies and a host of other fallacies. Feel free to restate your question, as it pertains to rational thought, using less polarizing examples.

So, does anyone know of a way to process the evidence rationally?

It's too difficult to be rational when trying to consider so many ideas at once. Focus on one, specific, well defined question and evaluate it and build up from there.

It might seem to be easier to try to evaluate large numbers of vague claims at once but that's because you aren't really evaluating them.

Look at long term trends. See this fantastic video showing why trends mostly support the optimistic view.

Eek.

Object level problem: I don't think the political landscape actually factors cleanly into the two categories you provided at all. E.g., if you'd asked me to provide two buckets to group people into, I'd have never thought to put "optimist" and "right-wing" on the label of the same bucket. The groupings you provide are not natural clusters in belief-space; at best they are accidents of history.

Meta-level problem: When people group things, typically they then ask "which side is most right", get an answer, and then staunchly defend that side (arguments are soldiers, that sort of thing). Really that whole "get an answer" step is just not a good operation, because both sides are likely to be more or less correct on different issues. You're much less likely to kill your mind if you just try to decide what the most correct position is for each issue without ever collapsing all that information down into "yay blue" or "yay green". Making the groups in the first place encourages that deadly collapse...

Now, I'm especially puzzled by the correlation between political sides what seems to be the Enlightenment/Romanticism divide. Where could it possibly come from?

Eh, the Enlightenment and Romantic backlash to it, perhaps? But I'm sure it didn't start then.

That is, ideas have genealogies too.

There are many explanations of this sort of divide out there. There are two I would recommend reading: first, Part I (Part II is mostly fluff) of A Conflict of Visions, by Thomas Sowell, and second, The Future and Its Enemies by Virginia Postrel. I recommend those two in particular because they look at this from very different lenses- Postrel uses terminology like yours, but Sowell uses almost the opposite terminology. (Which is, incidentally, a reason to read Sowell's first.)

Not sure how to say this without excessive partisanship, which I don't desire.

My first response to your essay is that I don't think your example of leftist intelligentsia (Noam Chomsky) is representative of all leftist thought.

Where did you find right wing optimism?

Our nation is dying, while others are multiplying like rabbits. The true faith lies in ruins, while false religions are spreading like wildfire.Our culture is vanishing under flood of Hollywood filth. Our history is smeared and slandered by liberal liars. Our leaders are either corrupt incompetents or willful traitors. The end is near.

When I read and listen to today's right wing, there is nothing than doom and despair all the time.