We've been going through all these ways we can become happier. We've talked about things we can do with our behaviors, with our thoughts, and with our feelings. But those are wonderful things to do, but we need to take into account one other thing if we want a full picture. It's something else that's naturally affecting this triad. These things interact within, our behaviors affect our thoughts and so on but there is an external agent that we need to pay attention to and that external agent is the situation. What do I mean by the situation? I just mean anything outside of ourselves that might be affecting our thoughts and our behaviors and so on. One of the deepthroughs of psychology is that the situation affects us more than we think. All of these factors outside of ourselves, the environment, and stuff, we assume that they're trivial, that they're just this thing outside of ourselves but they wind up affecting fundamental aspects of the way we think and the way we feel in ways we don't expect. We think it's just some background stuff, but in fact, it's affecting us more than we think. Let's take an incredibly trivial example that matters a lot. Let's take the weather situation. We're all having this conversation today when it's very hot in New Haven. It's a really sunny day outside and you might think that's just incidental thing. If it's sunny versus it's really rainy in New Haven. That's not affecting deep aspects of your decisions and your thoughts. Well, it might, and in fact, smart musicians like Joni Mitchell thought that, she said there were all these things that she would have done but the clouds get in the way. Is this really true? Do the clouds actually get in the way? Well, let's look at a case of a decision that you might think of as being very important, whether or not someone decides that you get into an Ivy League school later. You assume that the people who are looking at this are looking at your SATs and your grades and really considering your AP scores very carefully, but could those admissions decision officers be affected by the weather? That is what researcher Uri Simonsohn looked at. He just compared your probability of getting in to say Yale when your application happens to be looked at on a nice day, a really sunny day like today versus your application happens to be looked at on a rainy day. What he finds when he looks at this is that your probability of being admitted is affected by the weather. In fact, you increase your probability of being admitted by almost 12 percent when your application is reviewed on a sunny day versus a cloudy day. Nothing you all can do to control that but if that's what's going on in admissions officers' heads, imagine what's happening to your own thoughts and decisions when it's rainy out. Upshot, Joni Mitchell was right. The clouds do get in the way. But the biggest situational effect that we experience isn't even the weather, it's the other people around us. Our social situation is an incredibly powerful factor in how we're feeling, what we're doing, and so on. We know this because there's a lot of evidence that humans are basically like chameleons. We naturally unconsciously and automatically take on the behaviors of other people, so much so that we notice people are copying one another like a chameleon. In fact, psychologists literally call this chameleon effect, which we'll define as people unconsciously mimicking the postures and facial expressions of the people around them. I won't do the experiment with you, but if I was to suddenly change how is sitting so I did this a little bit more or I like crossed and uncrossed my legs. The evidence suggests that especially since I'm a teacher, some of you would be naturally and unconsciously copying those postures. This is what researcher John Barge and his colleagues find. We're soaking up everybody's behaviors without us realizing it but it's not just other people's behaviors and that makes sense. If you're copying my behavior, if I'm smiling a little more and you're smiling a little more, that might be affecting not just your behavior, but it might also be affecting your emotions. That's what we know is that in addition to being a chameleon for other people's behavior, we're also a chameleon for other people's emotions. This is what researchers call emotional contagion. It's just this phenomenon that emotions of the people around you are things you tend to soak up automatically and without realizing it. One of my favorite examples of this comes in the context of an emotion that we often experience, which is humor, things like laughter. If you see people laughing, you're more prone to laugh, and in fact, you don't even need to see them laughing. You can just hear the sounds of laughter. This is why television shows use a laugh track. You think it's annoying and I won't extra laugh, but the data suggests you really will. You can tell this because if you remove the laugh track from television shows, you start to see how deeply unfunny they are. Fun fact about laugh track, which I discovered when doing a whole podcast episode about laugh tracks, it turns out the laugh tracks that people use in modern sitcoms were made in the 1950s. They just never updated them because they worked and it turns out all the people you hear laughing are dead. They've been dead for decades. It's extra creepy that way. But we contagiously pick up other people's laughter but there's this question about whether we're contagiously picking up other people's emotions all the time. If you think about the emotions that you are exposed to, it's not just a 1950s laugh track on some television show. You are in the midst of social media feeds that are exposing you to emotions all the time. If you scroll through some angry feed or somebody who's experiencing depression, you would like to hope that you're not soaking all those emotions up, but are you? The answer from research seems to be yes. In fact, there was a famous and very controversial study by Kramer and colleagues that tried to look at this on Facebook. These researchers got Facebook to agree to change people's Facebook feeds. They didn't post fake parts of the feed, but they just changed the content a little bit. You'd have your normal feed of what people are posting and what they did was they either removed some of the positive posts so you just saw statistically less positive posts or they removed some of the negative ones. They're not adding anything. They either just take out some of the negative or they take out some of the positive at random and then they look at what you post. They're not looking at your emotions, they're just measuring, what do you say after that? This is the graph that I'm going to show you. First, I'm going to show you the number of positive words when these posts got the negativity reduced, that's on the left versus the positivity reduced and the gray bars are when this happens and the other is a control case where they just randomly pull out some parts of your feed. What you find is that if I'm looking at what you are posting, you are posting more positive words when I take out your negativity and you're posting less positive words when I take out your positivity, that's for positive words, but we can see the same effect even bigger in the case of these negative words. You don't realize it, you're just getting a little bit less negativity in your feed and that is affecting what you yourself post. We're soaking these things up on the social media apps that we engage with and we're soaking it up from the people around us. We don't realize other people's behavior and emotions are affecting us, but they really are. If you're around other people that are feeling stressed, you're going to soak that up a little bit whether you realize it or not. We've just seen that other people can affect our emotions really deeply but other people can also cause us to do some bad stuff. We have a word for this when other people affect our behavior, this is the idea of what's called conformity. This is when we match our attitudes and our behaviors to that of other people. This is the idea is if all your friends jumped off a bridge, would you do it too? The evidence suggests that in fact, meme, we're going to do it too. That's just what our minds are built to do. Other people are negatively affecting our behavior. They're causing us to do bad things and in some cases where people not like us do stuff, it could cause us to do good things. That raises the question of how should we be using other people's behavior to enhance our own happiness and to behave in ways that we want to behave.