It might seem obvious that smarter people attain more truth. I don't think that's true. I see intellectual honesty as the prime driver of truth attainment, and intelligence is a stimulant to however much intellectual honesty one does or does not bring to the table.
If you have both intelligence and intellectual honesty then you will find the most truth. (1st best)
If you have intelligence but not intellectual honesty then you will find the least truth. (4th best)
If you don't have intelligence but have intellectual honesty, you will find more truth (2nd best)
If you don't have both intelligence and intellectual honesty, then you will find less truth. (3rd best)
What do I mean by intellectual honesty? I mean care that one is reasoning for the purpose of true conclusions rather than preferred conclusions. Intellectual honesty is rooted in integrity, which I define as a concern for consistency. If one has integrity then they will be intellectually honest so they can live with consistency between thoughts, between thoughts and actions, and between thoughts, actions, and what one says.
In this view, intellectual honesty will always give you more truth than intellectual dishonesty. Intelligence, on the other hand, will pair with either intellectual honesty or intellectual dishonesty to give you even more truth or even less. Intellectual honest people use intelligence to find truth. Intellectually dishonest people use intelligence to argue for their desired conclusions.
It's rarely explicit. Nobody thinks to themselves, "I'm going to lie to myself about this." Integrity is a value that, under our cognitive hood, competes with other values. If you value consistency less than, say, community, then you'll naturally use your intelligence to find conclusions that get along with other people rather than attain truth. If you value consistency less than, say, being right, then you'll naturally use your intelligence to find the conclusions you started with. If you value consistency less than say, status, then you'll naturally use your intelligence to find conclusions that associate you with high status. Perhaps these are conclusions that agree with your boss, or are the conclusions other smart people have come to.
All these competing values are spectrums that we tradeoff on the margin. The more you care about community compared to consistency, the lower your non-conformity budget will be. You might spend some of that budget on some unusual beliefs that separate you from your groups, but you can only tolerate so much of society's disdain before you won't take on any more controversial ideas.
I'm a radical non-conformist. I take on many unpopular beliefs because they seem right to me. That's because of some combination of not valuing other things like community very much, and valuing consistency a lot. I would like to believe that it's because I value consistency so much, but I worry that it's more about not sufficiently appreciating other values like community or status. While I used to have a strong desire to have friends, it seems like I don't anymore. I spend very little time considering my general friendlessness and few resources trying to resolve it. And I've written a post that illustrates a disgust with status seeking.
On the other hand, my willingness to consider that my true motive is not integrity is a deeply integral thing to do. I don't spend many resources on social utility, but maybe it's already satisfied by the highly sociable kind of work that I do. Maybe my written criticism of status was mostly concerned with the way status-seeking crowds out integrity. It wasn't about not valuing status itself, but how much we have to give up in order to have it.
Anyway, I don't even know what valuing something more or less even means if it's not in regard to other values. Is it possible to value something more without valuing anything else less? Can one have more or less total values?
I place a high probability that I'm smart but not really smart (80% confidence my IQ between 115-135). Sometimes people in my life think I'm really smart, but I think they're actually perceiving one or several personality quirks. Rationality is not intelligence but a strange set of values. I think it yields me more truth than intelligence would, but I pay for it in other ways.