Epistemic status: I wish I'd thought of writing this before the day rolled around. Brief and unpolished, although this is something I've thought about a lot on both personal and computational neuroscience levels. There are no strong conclusions, just some thoughts on gratitude you may find interesting or even useful.

Hopefully you've had a fun Thanksgiving celebration, including feasting and appreciating family and friends. You may have even spent a little time thinking of the things you're grateful for. This seems like a pretty useful thing to do.

Gratitude is one of the best ways we know of so far to increase happiness, particularly in time/effect tradeoff. Keeping a journal of things you're grateful for, and writing in it daily is the most common intervention; it seems to work pretty well for some people, but I've never tried it.

Not only does gratitude seem to work empirically to increase happiness, it should work, for pretty deep theoretical reasons.

Minds like ours, a gamush of neural networks using predictive and reinforcement learning, need to keep track of what's good and bad. They need to learn to do things that make their outcomes better. That requires judging not only what's good, but what's better-than-expected. That in turn almost inevitably creates a comparative basis for happiness/joy/satisfaction. Evolution does not want us sitting around being happy with outcomes just as good as last time; it wants us to strive for better!

But evolution is not entirely the boss of us.

The world is too complex for our monkey brains to make a fully accurate objective judgment about what's a better-than-expected situation. Attention is going to play a huge role, by selecting some part of the complex world on which to make that judgement. And in our hyper-complex social world, we've got a lot of leeway in using attention strategically to get the results we want.

Danger! you say. This sounds like distorting our epistemics!

Well, sort of, but just in a specific way that seems like it should be thoroughly harmless if done correctly.

When I think "wow I'm grateful for my comfortable warm clothing", the fact that I have comfortable warm clothing is an accurate fact about the world. Whether or not I'm lucky to have them can be an epistemic question, but only with further framing: lucky compared to whom or what hypothetical? It's that framing that makes a fact about reality into a gratitude (and the emotional response; a little more on that below).

Were I to somehow force myself to believe that the world is really good, that would probably be distorting my epistemics. But gratitudes are not that. They are selecting a piece of the world, and focusing on a framing in which it is reasonable to feel grateful for the world being that way. There are likely other framings that could make that same thing about the world not gratitude-worthy. The choice of framings/comparisons isn't part of your actual model of the world.

(You'll probably recognize this as having a lot of overlap with Buddhist ideas; I originally started thinking about it when reading Zen theory, but it fits nicely with computational neuroscience as well).

This makes the practice of gratitude a deeply personal exercise. Trying to force yourself into a framing that doesn't make sense won't work. And you may have some emotional reactions that prevent you from sinking into and feeling pretty reasonable framings. Trying to be grateful for your warm clothes might draw your mind to the plight of homeless people without that good fortune, and feelings of guilt for not helping them more. Choosing framings for which I obviously don't bear responsibility seems useful to me; I'm grateful mostly for things I have that primitive humans did not (wow life would have been uncomfortable for tribal people, a lot of the time!).

The other part of successful gratitudes is strengthening the feeling of being grateful. The framing is one way to do that. For me, this can be enhanced pretty dramatically by what I think of as "direct emotional induction". I imagine what it feels like to feel the emotion I want (in this case, gratitude; often, joy; I just tried anger to verify that it's a general technique for me and wow, yuck).

I personally think this is taking advantage of the way executive function and working memory works in the brain; it's opening recurrent loops between the prefrontal cortex and basal ganglia, which keep the neural populations that represent a concept or approach active. They seem represent those concepts (or strategies or whatever, in this case emotions) by having bidirectional connections with the neural populations in the rest of the brain that enact those concepts/strategies/whatever. So keeping them firing is directly activating that other stuff.

That's (rather well-informed) speculation; we'll know for sure if we survive the singularity. And it doesn't matter. It's a thing that seems to work for me, maybe it will work for you.

One final note on approach: I've never done a gratitude journal because I'd rebel against any such task I set for myself. I have instead used a different approach I've used for other types of habit development: post-it notes or other visible reminders that catch my attention. (My mother suggested this to me when my brother and I were conceptualizing a rather complex habit-changing app that wouldn't have worked nearly as well. Maybe it's part of known self-help.) 

This works for me only if I believe in the process enough to do the exercise when I notice the reminder, at least some of the time. And the location and ultimately the reminder has to change pretty frequently for me to even notice it; my brain tunes it out as expected in maybe a week to a month. Again, this seems to work for me, it might be useful for you. Or not.

Make of it what you will!

There are lots of other routes to happiness; How to Be Happy seems like a good overview from a rationalist perspective (although probably there's new relevant science in the 14 years since).  Empirically, gratitudes (as studied) work better for some people than others; other approaches are more productive for some. I'm writing about gratitudes because it's the thing I've thought about and subjectively benefitted from most. And hey, it's Thanksgiving!

I've developed a habit of doing mini-gratitudes spontaneously, and using reframing and direct emotion induction to change my feelings when I think they're not productive. It works well but far from perfectly for me. 

Sometimes negative emotions are doing their job properly and shouldn't be tampered with. If you overdo it on enjoying things, life will at some point remind you. And you should be careful you're not distorting your epistemics by telling yourself things are different than they really are. You can probably convince yourself with some work, and you probably shouldn't. But access to better (or different) outlooks/framings/comparisons, and a habit of using it, seems useful to me.

I'm grateful to be connected to a community of rationalists who also happen to overwhelmingly have really good hearts.

Happy thanks giving.