Which ideas from LW would you most like to see spread?

That they notice when they are arguing about definitions, and not do that.

To other Internet forums:

I think evidence-updating is kinda common, what striked me as really new here is tabooing.

So that one. Not getting too hung up about terms / categories. I would be happy enough if at least the habit of doing a quick round of taboo whenever anyone feels a discussion is too attached to terminology would be widespread on places like Reddit.

For example, I kinda like economics. This is why I absolutely hate it people use "capitalism" as a flag to rally for or against, and then quality goes down the drain, it all becomes a playground fight. We all know (or if engaging in these issues, then should) that it unpacks to two different and unrelated terms, one is broadly a voluntary transactions based system, and the other is a specific distribution of property where most people don't have any so they need jobs offered by those who have. It would be so easy to not use this word just use the appropriate unpacking.

There is something about all this tabooing thing that reminds me of when I used to be a fairly active Buddhist. Similar things were done.

Personal life, living better:

Tough question, but probably not trying to be "clever". That is, not ranking solutions on the complexity or how sophisticated they look but more like accepting, taking, or coming up with "boring advice". There is a HUGE urge to show off your brain sparkles if you have an IQ over 120 and this can be highly counter-productive. It is really humiliating and enlightening to see how more efficient people can be who are not trying to be too clever. I know a guy who is a textbook average mind, works in a warehouse, likes football, not much else. They wanted to live in the UK and did it so that he moved, got a job, and then his girlfriend follow a few months later. Anyway he figured it is time to lose some weight and he was not much into cooking anyway, so he just filled a big tupperware every 2-3 days with sliced cucumbers and tuna from cans and that salad was the only thing he ate. It was, of course, very efficient, having found two of the least calorie dense foods that exist. And yet there are intelligent people who struggle with their weight for decades with the most complicated insulin response based diets. Committing hard to something simple is often the best - just the problem is that it lacks glory, hence, motivation...

My most pleasant experience here was that people listen to your arguments if you make the effort / do your homework, even if they are contrary to their ideological views.

When I wrote something which (knowing the statistics about the demographics who frequent this site) was opposing the ideological views of the overwhelming majority of the target audience of the site (and even involved religion in a limited way), the reaction was not what you find on most other sites where they denounce you as the Enemy, cherry-picking some of your arguments they can counter and pretending they didn't notice the ones they can't, and even if they found something in your arguments they can agree with it, they never admit because that's impossible, as you are the evil Enemy and everything you say must be wrong by default... no, instead of this most people actually listened, and while they stated those parts they disagreed with, they admitted that they agreed with parts of it and even admitted that they had to update at least part of what they knew or believed about the topic.

A lot of online communities pay lip service to the idea that their experiences aren't universal, but Less Wrong seems to be one of the few places that takes that idea seriously.

The difference between "I don't think that's true" and "I disapprove of the policy implications of that".

Steelmanning, and tabooing words.

But neither of these were invented here.

Understanding much communication as glorified signalling, and specifically Applause Lights.

EA.

Working habits for making unusually low levels of dishonesty work outside relationships and small select groups.

Scholarship: How to Do It Efficiently by lukeprog

Immortality: A Practical Guide by G0W51

JonahSinick's many many many many posts on career advice

More knowledge about bias, which would particularly undermine the unfortunately common and well regarded stance "I only believe what I see". People rely too much on their direct feelings/intuitions without assessing them.

The idea that in order to have an accurate representation of reality, one must have background knowledge in science. Add in a little philosophy (recent philosophy, like Popper).

Also praising the ones who admit their mistakes - that happens too little.

The final idea would be like yours, more Bayesian thinking.

I'm probably too optimistic.

Extremely difficult to get into normal people's heads: that striving to become more rational has nothing to do with becoming "less emotional."

One of the key abstract memetic components of LW is something along the lines of "use recent research findings about cognition from fields like psychology, artificial intelligence, probability, and economics to improve your own thinking." That seems like an idea worth spreading. People could use that idea even if they didn't accept or understand specific individual techniques like value-of-information calculations.

The idea that I find least entangled but still very potentially beneficial is that politics is the mind-killer. I realize it's an old sequence, and it doesn't have much traction here (since LW is ostensibly un-killed minds).

An idea that I think would be very helpful to people - and relatively simple to grasp - is the idea of tribalism, and how much it really motivates us, even to this day. Not just that politics is the mindkiller, but why. I think if more people were able to take a step back every once in a while and think, "Hey, I don't even care about or like this idea...why am I defending it? Because it's an idea that I think a group I consider myself a part of holds, and by attacking one idea of my tribe, it seems like you're attacking every idea of my tribe? Does this make sense?" then the world would be a much more friendly place, at least.

Understanding the distinction between the map and the territory. And understanding that there are different levels of maps.