Bears resemblance to: Ureshiku Naritai; A Suite of Pragmatic Considerations In Favor of Niceness

In this comment, I mentioned that I can like people on purpose.  At the behest of the recipients of my presentation on how to do so, I've written up in post form my tips on the subject.  I have not included, and will not include, any specific real-life examples (everything below is made up), because I am concerned that people who I like on purpose will be upset to find that this is the case, in spite of the fact that the liking (once generated) is entirely sincere.  If anyone would find more concreteness helpful, I'm willing to come up with brief fictional stories to cover this gap.

It is useful to like people.  For one thing, if you have to be around them, liking them makes this far more pleasant.  For another, well, they can often tell, and if they know you to like them this will often be instrumentally useful to you.  As such, it's very handy to be able to like someone you want to like deliberately when it doesn't happen by itself.  There are three basic components to liking someone on purpose.  First, reduce salience of the disliked traits by separating, recasting, and downplaying them; second, increase salience of positive traits by identifying, investigating, and admiring them; and third, behave in such a way as to reap consistency effects.

1. Reduce salience of disliked traits.

Identify the traits you don't like about the person - this might be a handful of irksome habits or a list as long as your arm of deep character flaws, but make sure you know what they are.  Notice that however immense a set of characteristics you generate, it's not the entire person.  ("Everything!!!!" is not an acceptable entry in this step.)  No person can be fully described by a list of things you have noticed about them.  Note, accordingly, that you dislike these things about the person; but that this does not logically entail disliking the person.  Put the list in a "box" - separate from how you will eventually evaluate the person.

When the person exhibits a characteristic, habit, or tendency you have on your list (or, probably just to aggravate you, turns out to have a new one), be on your guard immediately for the fundamental attribution error.  It is especially insidious when you already dislike the person, and so it's important to compensate consciously and directly for its influence.  Elevate to conscious thought an "attribution story", in which you consider a circumstance - not a character trait - which would explain this most recent example of bad behavior.¹  This should be the most likely story you can come up with that doesn't resort to grumbling about how dreadful the person is - that is, don't resort to "Well, maybe he was brainwashed by Martians, but sheesh, how likely is that?"  Better would be "I know she was up late last night, and she does look a bit tired," or "Maybe that three-hour phone call he ended just now was about something terribly stressful."

Reach a little farther if you don't have this kind of information - "I'd probably act that way if I were coming down with a cold; I wonder if she's sick?" is an acceptable speculation even absent the least sniffle.  If you can, it's also a good idea to ask (earnestly, curiously, respectfully, kindly!  not accusatively, rudely, intrusively, belligerently!) why the person did whatever they did.  Rest assured that if their psyche is fairly normal, an explanation exists in their minds that doesn't boil down to "I'm a lousy excuse for a person who intrinsically does evil things just because it is my nature."  (Note, however, that not everyone can produce verbal self-justifications on demand.)  Whether you believe them or not, make sure you are aware of at least one circumstance-based explanation for what they did.

Notice which situations elicit more of the disliked behaviors than others.  Everybody has situations that bring out the worst in them, and when the worst is already getting on your nerves, you should avoid as much as possible letting any extra bubble to the surface.  If you have influence of any kind over which roles this person plays in your life (or in general), confine them to those in which their worst habits are irrelevant, mitigated, or local advantages of some kind.  Do not ask for a ride to the airport from someone who terrifies you with their speeding; don't propose splitting dessert with someone whose selfishness drives you up the wall; don't assign the procrastinator an urgent task.  Do ask the speeder to make a quick run to the bank before it closes while you're (ever so inconveniently) stuck at home; do give the selfish person tasks where they work on commission; do give the procrastinator things to do that they'll interpret as ways to put off their other work.

2. Increase salience of positive traits.

Don't look at me like that.  There is something.  It's okay to grasp at straws a little to start.  You do not have to wait to like someone until you discover the millions of dollars they donate to mitigating existential risk or learn that their pseudonym is the name of your favorite musician.  You can like their cool haircut, or the way they phrased that one sentence the other week, or even their shoes.  You can appreciate that they've undergone more hardship than you (if they have, but be generous in interpreting "more" when comparing incommensurate difficulties) - even if you don't think they've handled it that well, well, it was hard.  You can acknowledge that they are better than you, or than baseline, or than any one person who you already like, at some skill or in some sphere of achievement.  You can think they did a good job of picking out their furniture, or loan them halo effect from a relative or friend of theirs who you think is okay.  There is something.

Learn more about the likable things you have discovered.  "Catch them in the act" of showing off one of these fine qualities.  As a corollary to the bit above about not putting them in roles that bring out their worst, try to put them in situations where they're at their best.  Set them up to succeed, both absolutely and in your eyes.  Speak to any available mutual friends about what more there is to like - learn how the person makes friends, what attracts people to them, what people get out of associating with them.  Solicit stories about the excellent deeds of the target person.  Collect material like you're a biographer terrified of being sued for libel and dreading coming in under page count: you need to know all the nice things there are to know.

It is absolutely essential throughout this process to cultivate admiration, not jealousy.  Jealousy and resentment are absolutely counterproductive, while admiration and respect - however grudging - are steps in the right direction.  Additionally, you are trying to use  these features of the person.  It will not further your goals if you discount their importance in the grand scheme of things.  Do not think, "She has such pretty hair, why does she get such pretty hair when she doesn't deserve it since she's such an awful person?  Grrr!"  Instead, "She has such pretty hair.  It's gorgeous to look at and that makes her nice to have around.  I wonder if she has time to teach me how to do my hair like that."  Or instead of: "Sure, he can speak Latin, but what the hell use is Latin?  Does he think we're going to be invaded by legionaries and need him to be a diplomat?" it would be more useful towards the project of liking to think, "Most people don't have the patience and dedication to learn any second language, and it only makes it harder to pick one where there aren't native speakers available to help teach the finer points.  I bet a lot of effort went into this."

3. Reap consistency effects.

Take care to be kind and considerate to the person.  The odds are pretty good that there is something they don't like about you (rubbing someone the wrong way is more often bidirectional than not).  If you can figure out what it is, and do less of it - at least around them - you will collect cognitive dissonance that you can use to nudge yourself to like the person.  I mean, otherwise, why would you go to the trouble of not tapping your fingers around them, or making sure to pronounce their complicated name correctly, or remembering what they're allergic to so you can avoid bringing in food suitable for everyone but them?  That's the sort of thing you do when you care how they feel, and if you care how they feel, you must like them at least a little.  (Note failure mode: if you discover that something you do annoys them, and you respond with resentment that they have such an unreasonable preference about such a deeply held part of your identity and how dare they!, you're doing it wrong.  The point isn't to completely make yourself over to be their ideal friend.  You don't have to do everything.  But do something.)

Seek to spend time around the person.  This should drop pretty naturally out of the above steps: you need to acquire all this information from somewhere, after all.  But seek their opinions on things, especially their areas of expertise and favorite topics; make small talk; ask after their projects, their interests, their loved ones; choose to hang out in rooms they occupy even if you never interact.  (Note failure mode: Don't do this if you can feel yourself hating them more every minute you spend together or if you find it stressful enough to inhibit the above mental exercises.  It is better to do more work on liking them from a distance if you are at this stage, then later move on to seeking to spend time with them.  Also, if you annoy them, don't do anything that could be characterized as pestering them or following them around.)

Try to learn something from the person - by example, if they aren't interested in teaching you, or directly, if they are.  It is possible to learn even from people who don't have significantly better skills than you.  If they tell stories about things they've done, you can learn from their mistakes; if they are worse than you at a skill but use an approach to it that you haven't tried, you can learn how to use it; if nothing else, they know things about themselves, and that information is highly useful for the project of liking them, as discussed above.  Put what you know about them into the context of their own perspective.

Note general failure mode: It would be fairly easy, using facsimiles of the strategy above, to develop smugness, self-righteousness, arrogance, and other unseemly attitudes.  Beware if your inner monologue begins to sound something like "He's gone and broken the sink again, but I'm too good and tolerant to be angry.  It wouldn't do any good to express my displeasure - after all, he can't take criticism, not that I judge him for this, of course.  I'll be sure to put a note on the faucet and call the plumber to cover for his failure to do so, rather than nagging him to do it, as I know he'd fly off the handle if I reminded him - it's just not everyone's gift to accept such things, as it is mine, and as I am doing, right now, with him, by not being upset..."

This monologuer does not like the sink-breaker.  This monologuer holds him in contempt, and thinks very highly of herself for keeping this contempt ostensibly private (although it's entirely possible that he can tell anyway).  She tolerates his company because it would be beneath her not to; she doesn't enjoy having him around because she realizes that he has useful insights on relevant topics or even because he's decorative in some way.  If you don't wind up really, genuinely, sincerely liking the person you set out to like, you are doing it wrong.  This is not a credit to your high-mindedness, and thinking it is will not help you win.

¹ A good time to practice this habit is when in a car.  Make up stories about the traffic misbehaviors around you.  "The sun is so bright - she may not have seen me."  "That car sure looks old!  I probably wouldn't handle it even half as well, no wonder it keeps stalling."  "He's in a terrible hurry - I wonder if a relative of his is in trouble."  "Perhaps she's on her cellphone because she's a doctor, on call - it then would really be more dangerous on net if she didn't answer the thing while driving."  "He'd pull over if there were any place to do so, but there's no shoulder."  Of course any given one of these is probably not true.  But they make sense, and they are not about how everybody on the road is a maniac!  I stress that you are not to believe these stories.  You are merely to acknowledge that they are possibilities, to compensate for the deemphasis of hypotheses like this that the fundamental attribution error will prompt.