Why Judging People You Don’t Know is Rude and Irrational

How to think wisely about interactions with others.


Your roommate gets back for the night and she’s a little salty. So she tells you the story.

She was studying with John and Megan in the Student Union. They were all having a good time and working on homework when all of the sudden, Megan says she’s heading back for the night. Then John says he will “walk back with her.” Well your roommate is pretty upset with that because she just met John and she was really looking forward to hanging out with John more and getting to know him. Now she thinks John is rude and that he doesn’t really like her very much.

You start getting all worked up as well and say “yeah I heard someone else tell me that he wasn’t really that nice of a person either! You just shouldn’t hang out with him anymore. Forget him.”

In this situation specifically, you have absolutely no right at all to judge John or what his motives are for taking the action that he did. In fact, you are now probably one of the most unqualified people to talk about John.

As humans, we are prone to a lot of cognitive biases and irrational thinking processes. Although you might say, “no way, I am a rational thinker!”, you’re not always right. You are prone to cognitive biases just like everyone else. While this situation I have outlined here might not have happened to you, there are dozens of other interactions you have throughout the day that take this very same form. With that said, I hope something in here will help you think more wisely about your interactions with others throughout the day and in the coming months.


So to get back to the situation, why are you so unqualified to talk about John in this case? There are a few reasons. The first one is context. Generally speaking, we discount the role of context in another person’s actions but acknowledge and increase its role when explaining our own actions. This is because context is always most salient (visible) to the actor.

The idea of context is that often other things besides our own desires and actions influence our decision making process. Many of these are part of ourconscious thought process. In this case, there could be multiple things circling around John’s head at that very moment that influence his end decision. Megan might have had a bad day today and needs someone to talk to. Or maybe he is just tired and wants to go to bed. Or many he didn’t actually think your roommate enjoyed talking to him very much.

There could be a myriad of factors influencing John’s behavior that you will never see or could see even if you wanted to.

However, context doesn’t only apply to the things that John was consciously thinking but also the things that he was unconsciously processing. Something else we discount is the role of unconscious thought process and context that affects a person’s actions without them even knowing. Maybe your roommate was cold the whole night and didn’t think anything of it while she had her arms crossed for much of the night. John didn’t consciously think your roommate was standoffish but his unconscious mind did which might have made the difference of him heading back with Megan or sticking around.

So not only are there things that John was consciously thinking that you know nothing about but there were also several other factors which even he didn’t know about that were influencing his decision.

Now the question is this: do you really think your roommate was able to distill all of those variables? Those being: the context of the situation and both conscious and unconscious variables that the other person was thinking through? I’ll answer that for you: there’s no way.

Let’s think more about how that information was delivered to you.

As your friend was walking back to your room, she was likely forming a lot of opinions about what just happened. She was probably figuring out how to word it to you so that you too would think that John is a terrible guy. And even if she didn’t consciously think that, she might have been unconsciously thinking that based on what happened.

It is easy enough to see that this information that you’re receiving is from a biased source.

Keep in mind: when you talk to people, know that anything they tell you is already biased by its very nature. All of the words coming out of their mouth have gone through their own internal thought process which has been tainted (for better or worse) by their own way of seeing the world.

Now you might ask, well what about a case where I see and interact with the person myself? What if you pass by John on the street when you’re walking with your friends? With a big smile you give him a “hey John, how are you doing?!?!”, just to show him how super friendly you are. He replies, “hey” and keeps walking.

Well now, of course, you have the right to say he’s a jerk.

Just kidding, no you don’t. Why not? Well, it could be context, as discussed above. Maybe one of your other friends and John don’t get along and he didn’t want to look at her. Maybe he was busy and had to get to a meeting. If neither of those are the case, you still can’t say he’s a jerk because of a beautiful and enlightening concept called reversion to the mean, referred to also as the law of large numbers.

You’ve probably taken a statistics class. If you didn’t pay attention, you should have. Statistics can help us better understand the world around us, including our interactions with others.

When we put this conversation of people’s attitudes and actions in perspective of statistics, it gives us a good framework from which to think about our interactions with other people on an everyday basis. The truth is, when you walked by John on the sidewalk, that is really only one interaction that you experienced during one day in his life. As you know, some days in life will be great, some days will suck. You have no idea on which day you caught John.

Below is an image of a normal distribution. The idea is that the mean of a persons behavior or personality traits will lie in the middle as how people act is really just an average of highs and lows. As this average is made up of many different days, at any given point when you meet someone, you could be looking at a bad representation.

Maybe you caught him on a rare day when he wasn’t himself because something was really bothering him. Maybe that interaction was over 2 standard deviations away from his normal actions, meaning that it was incredibly rare and uncharacteristic of him.

The same can be said for your roommate in the situation discussed above. If she doesn’t know John very well, she could be basing her entire conception of him on a skewed sample which was skewed even more once she gave it to you. THAT is why you are not in any sense able to speak proficiently about John and his personality.

However, over time, as you interact with John more, there will be a reversion to the mean and you will be able to understand more of how he operates.


To reinforce this idea, the graph below is taken from a book called Mindware. The author did an experiment in which he looked at the correlation between people’s abilities and traits between one instance to another and from the total of instances to another total. He then asked others what they expected the correlation to be. What he found is graphed below.

Let’s start on the left side. Here we can see that one instance of ability is correlated about .5 with any other given instance, e.g. if the basketball player is good one day, that is a okay (still not perfect) predictor of his ability to be good another day. However, when compared to the total amount of data, the law of large numbers / concept of reversion to the mean kicks in and the correlation is incredibly high. If we look at the difference between people’s guesses and the actual data, it isn’t all that far off.

Now looking over at the right side, look at the huge disparity between the actual data and what people guessed! To put the “item to item” data in layman’s terms, people vastly over expect that a single instance of a persons personality is a good indicator of their overall personality, e.g. when someone is nice to you right when you meet them, it is incredibly wrong to assume that they will always be that way, or that your interaction was a good proxy for knowing them well. On the flip side, when you meet someone and you’re put off by them, that’s a terrible proxy for their overall personality. Any interaction is just one data point among many.

We think we learn much more than we do from a small sample of a person’s behavior because we are inclined to underestimate the possible role of the context and because we think behavior on one occasion is sufficient to make a good prediction about behavior on the next, possibly quite different occasion.

With all that being said, the ONLY way you can make any kind of rightful judgement about a person and their actions is if you personally observe, the same behavior, within the same context, over multiple time periods. Then and ONLY then, can you make any kind of judgement.

Even at that, you could be reaching a conclusion about the person that is unfair. So do you know what the best solution is?

Talk. to. them.

While analyzing someone’s behavior over a period of time can be helpful, you’re going to learn so much more if you sit down with them and talk face to face.

So think right now about those people who you have negative opinions of but don’t actually know that well. Have dinner with them, do homework with them, grab coffee. You’ll likely walk away understanding why the person acts the way they do much better than before. But even at that, realize that your coffee date itself could give you a skewed sample.

So what’s the point of sharing all of this? What do I hope you take away from my ramblings? Four things.

  1. Just as you have many different influencing factors within the context of your decisions, so do other people, don’t discount theirs.
  2. Understand that one interaction with another person is just one data point among many. Discount those interactions with whom you haven’t interacted with very much. You probably have a skewed sample.
  3. Do your own work. Don’t rely on others to tell you about a person. Spend time talking TO one another instead of talking ABOUT one another.
  4. Your assumptions are usually wrong.