We all know that person: the Mr.Always-right co-worker, who always thinks he’s got it down and everyone else is wrong. The self-victimizing acquaintance who thinks she treats everyone generously and kindly but who everyone else treats like dirt. The friend you grew up with who thinks he’s reflective and everyone else needs to learn that skill.

At some point in our lives, we will come across the self-righteous person. With their criticism, indignation, and conceit, they tend to grate on our nerves and throw us off our track—if we let them.

But what is the psychology behind the self-righteous personality, and how does it affect you when you have to deal with that BS?

A number of variables grow the self-righteous mind, but a few characteristics are shared by those who think they’re oh-so-good-and-right:

1. Overgeneralizations: Take a negative incident, throw some magic growth-powder on it, and you have an exaggeration. Look out for “always”, “never”, and “all” from these people, and you could have some self-righteousness burbling in the cauldron.
2. Positive-discounting: On the flip side of overgeneralizations is taking the stance that positive things, like characteristics of others, aren’t as important. “Hey, you’re nice, but who cares. Being nice is overrated, anyway.”
3. Jumping to conclusions: We all do it, but the self-righteous person is skilled in this. Conclusions are arrived at, though there is very little to no non-bias to the conclusion. “So-and-so didn’t give me money as a Christmas present this year; they don’t care about me and are cheap. Ugh, I hate cheap people.”
4. Black-and-white thinking: Either you’re perfect, or you’re not. If you fall short of expectations, it’s because you’re not [insert some quality here], and that’s a reflection of your entirety.

Of course, the self-righteous person doesn’t always have to share these qualities, and their behavior may not draw from these thinking patterns. I know some people who seem self-righteous, and perhaps they are, but it’s due more to social environment than anything else. That’s not to say they haven’t adopted the self-righteous attitude, but I don’t think they would’ve turned out that way had it not been for certain social attitudes around them.

But what makes the self-righteous attitude such a pervasive form of thinking for those who engage in it?

There are a number of reasons based on basic human psychology.

The backfire effect is a relatively common human tendency to protect whatever is added to your collection of beliefs. That is, whatever you decide to believe, you tend to dismiss what doesn’t match up to that perspective, and suck in the “evidence” that matches up to it. So you end up glued to your beliefs and never questioning them, even when new information comes your way that shakes up the foundations of those beliefs—or rather, could shake those foundations if only the backfire effect didn’t get in the way.

The backfire effect is mostly due to cognitive laziness—our brains don’t want to work, so we sink into those explanations that don’t take too much energy to process. The more strenuous it becomes to process things, the less credibility you think they have.

Think you don’t have this tendency yourself, though? Think again.

The next time you have someone praise you, then another person criticize you, explore how you feel. Chances are, a thousand “You’re so smart”, but one “You’re not smart enough” will affect you differently. You’ll let the praise slip right through your mind, but you’ll leech on to the negative comment.

Why?

The backfire effect and another tendency have something to do with it. People tend to spend more time considering information they disagree with than information they accept. Anything that lines up with your way of thinking passes through your processing simply, but anything that threatens your beliefs will grab on to your awareness and hold on. With the backfire effect in play as well, you’ll end up not believing the harder pill to swallow, because it ends up taking too much energy to process. Even if you dwell on the criticism, you’ll fight against believing it and try to find all the ways that that criticism is wrong about you.

Why is this so? Evolution may be at play, here.

Our human ancestors paid more attention to negative stimuli than positive, because if the negative wasn’t addressed, that could mean death.

Biased assimilation has something to do with all this, as well. Kevin Dunbar ran an fMRI experiment where he showed subjects information that confirmed their beliefs about something. Brain regions relating to learning lit up.

But when given contradictory information, those learning brain regions didn’t light up. Rather, brain regions relating to suppression lit up.

In other words, presenting information doesn’t necessarily change the way people think or what they believe. We’re all susceptible to cognitive biases—some of us more so than others.