I think it a common misconception that people are liked (or disliked) primarily due to their character, abilities, or personality. I believe, rather, that it is the impact of one person on another’s feelings about himself that will determine whether the second person finds the first attractive or not. This has implications.
Doing It Wrong
To begin with, if you’re trying to be likable by making a show of your virtues (or, even worse, talking yourself up) then you’re doing it wrong. No one is that interested in you, and, even if you succeed in making yourself look good, you’re likely to drive others away by making them look bad by comparison.
Balanced against this is the fact that it’s good to be seen as useful; people want to associate with those who can solve their problems. A little usefulness goes a long way, however — there are lots of people who can solve problems, do good work, turn out reliable results, and so on. If the price of demonstrating your usefulness is offending those around you, you’re undermining yourself in the long run.
Self-promotion is a tricky thing, as it’s always better to let other people conclude that you’re valuable on their own, as opposed to telling them all about it. I think it’s best to focus on producing results and being personable. In general, if you are useful, and if people like you, they’ll figure out your virtues for themselves; there’s no need to make a spectacle of yourself. Once others have drawn the desired conclusions, you can reap the benefits of their high opinion, without the costly side-effects of “yay-me-ism”.
A consequence of all this is that real intelligence is likely to be fairly attractive. It’s been my experience that truly clever people have the ability to present matters so clearly that they impart understanding to those around them, making those people feel intelligent in turn. In fact, a reasonable definition of intelligence is the ability to make complex things seem simple.
The point of all the qualifiers in the preceding paragraph (“real”, “truly”) is that fake intelligence — flashy attempts to appear more clever than you are — are likely to backfire. In the first place, you can’t fake someone else’s feeling of understanding. In the second place, no one likes a braggart. So, if you’re lucky enough to be clever, don’t waste your time trying to prove it.