But their motivations can be hard to understand from their own point of view. I guess it's mostly because I can't be bothered to find out...

I used to have trouble understanding humans, but then I devoted a hobby-slot worth of effort to the problem, and it went away. Your brain, like mine, might have trouble handling social interaction by default, but if you devote sufficient attention, you may well make progress, perhaps even significant progress. In my experience, many nerdy people who claim to have trouble understanding people don't direct anywhere near as much cognition towards social interaction as they do towards the things they are good at.

Don't just try to understand someone's motivations when you run into some sort of difficulty or challenge with them. Try to understand every single person you meet and try to see the world through their eyes.

You need to accrue enough data that you can start seeing patterns. Over time, you may be able to evaluate people faster and faster until eventually you will just get an intuition or a feeling about them.

In the Star Wars novels, Grand Admiral Thrawn studied the art of species he fought to understand their psychology better for his military strategy. Listen to popular music and watch popular TV shows and movies. These media appeal to human beings with modal cognitive architecture. With enough exposure, these media might resonate with you. You may be able to cognitively reverse engineer people's mental architecture. Media has a message, and people consume media because that message appeals to their motivations and emotions. Why is this?

You get a certain emotion when you listen to a song (if it's a popular song, you probably don't like it, I would guess based on what you've revealed so far). Do other people like experiencing that emotion? If so, why? Or are other people getting a different message from the song? If so, what sort of mind and motivational/emotional structure might they have such that the emotional and conceptual message of the song appeals to them?

Make hypotheses about people, and try to test them. For example, make a guess about someone (their taste in music, their goals in life, what type of people they are attracted to, how they will act in the ongoing situation) and try to see if you are right.

Some knowledge of psychology, such as the Big Five are useful for generating hypotheses about people. A starting point that I found very helpful for understanding people is the Lenore Thomson Exegesis Wiki. It is a guy theorizing about Lenore Thomson's theories about Jungian psychology. This stuff isn't very scientific, but if you can get through all the acronyms (or just ignore them), it has some insightful ideas about how people might be different from each other.

For instance, on this page, Introverted Thinking sounds like me:

Introverted Thinking (Ti) makes sense of the world by apprehending it in terms of effects emerging from a cause, or a harmony of elements. For example, the way a beautifully made desk appears to emerge from a single idea. As an epistemological perspective, Ti leads one to trust only things that you understand first-hand for yourself, preferably through direct, hands-on interaction. You must see for yourself how a given thing or subject makes sense. Knowledge must emerge from the concrete reality itself, not from preconceived categories or criteria, and the search for knowledge must follow wherever logic and the subject matter lead, regardless of how people feel about it.

Extraverted Intuition also sounds like me:

Extraverted Intuition makes sense of the world by seeing ways to incorporate what is known into a broader context--breaking through the limits of current concepts. For example, sensing, before nearly anyone else, that high-bandwidth communication networks would "change the rules" of commerce. As an epistemological perspective, Ne leads you to practice "out of the box" thinking. There are never any final answers, just more and more opportunities to shift concepts and make sense of things in new ways. Whatever we think things mean today, we'll probably find out tomorrow they mean something different. As an ethical perspective, Ne leads you to take risks and dive into the unknown--stacking the deck to some extent by diving into areas that look especially fertile, but genuinely entering the unknown and allowing it to send your mind in new directions. If you don't know, just guess! Try something, and information will come to you--but only if you stir up the pot. From an Ne perspective, life is a succession of opportunities to pounce on, each opportunity opening up more that you can't yet see.

In contrast, I don't relate so much to Extraverted Sensation:

Extraverted Sensation (Se) makes sense of the world by attending to what exists concretely here and now, and trusting your instincts. As an epistemological perspective, Se leads you to believe only in what you can see and experience concretely, and to trust your immediate, gut-level responses to it. If it looks like a duck, walks like a duck, sounds like a duck, then it's a duck. Whatever a sign means is obvious and inescapable; if a sign's meaning is not obvious, then it's meaningless. Whatever is physical, immediate, gut-level cannot be faked and must be right. For example, if you sense that someone is up to no good, then you trust that sense. If you have an impulse to paint the town red, then you go out and do so.

...but I can easily think of people who act in a way that could be explained by having this motivational system. And I can relate to this sort of motivation myself, even though other motivations tend to trump it.

Other pages to read:

• http://greenlightwiki.com/lenore-exegesis/Cocooning-vs.-Conforming_Exegesis
• http://greenlightwiki.com/lenore-exegesis/Place-Your-Stakes_Exegesis
• http://greenlightwiki.com/lenore-exegesis/Truth-and-Language_Exegesis
• http://greenlightwiki.com/lenore-exegesis/Why_Mathematics_Is_Unpopular
• http://greenlightwiki.com/lenore-exegesis/Political_Correctness

Reading every article on that wiki about 5-10 times taught me more practical knowledge about humans than anything I ran into in college psychology classes... but it's pretty opaque and not for everyone.

Anyway, once you get a better sense of other people's emotions and motivations, then you can practice imagining those emotions/motivations, relating to them, or even feeling them yourself.

• Music, movies, dance and art are a good place to start for shifting your emotional state towards others.

• Socialize a lot.

• Copy the facial expressions that other people make (even in front of the mirror). This may trigger biofeedback and cause you to feel the same way they did when they made that expression.

I realize that the process I'm describing takes work, but for me, it was about a hobbie's worth of work. Just make people your hobbie for a while. It helps if you can enjoy this hobbie as a challenge. People are actually a really fun puzzle.