A couple of weeks ago, I was suffering from insomnia. Eventually my inability to fall asleep turned into frustration, which then led to feelings of self-doubt about my life in general. Soon I was wondering about whether I would ever amount to anything, whether any of my various projects would ever end up bearing fruit, and so forth. As usual, I quickly became convinced that my life prospects were dim, and that I should stop being ambitious and settle for some boring but safe path while I still had the chance.

Then I realized that there was no reason for me to believe in this, and I stopped thinking that way. I still felt frustrated about not being able to sleep, but I didn't feel miserable about my chances in life. To do otherwise would have been to misinterpret my emotions.

Let me explain what I mean by that. There are two common stereotypes about the role of emotions. The first says that emotions are something irrational, and should be completely disregarded when making decisions. The second says that emotions are basically always right, and one should follow their emotions above all. Psychological research on emotions suggests that the correct answer lies in between: we have emotions for a reason, and we should follow their advice, but not unthinkingly.

The Information Principle says that emotional feelings provide conscious information from unconscious appraisals of situations¹. Your brain is constantly appraising the situation you happen to be in. It notes things like a passerby having slightly threatening body language, or conversation with some person being easy and free of misunderstandings. There are countless of such evaluations going on all the time, and you aren't consciously aware of them because you don't need to. Your subconscious mind can handle them just fine on its own. The end result of all those evaluations is packaged into a brief summary, which is the only thing that your conscious mind sees directly. That "executive summary" is what you experience as a particular emotional state. The passerby makes you feel slightly nervous and you avoid her, or your conversational partner feels pleasant to talk with and you begin to like him, even though you don't know why.

To some extent, then, your emotions will guide you to act appropriately in various situations, even when you don't know why you feel the way you do. However, it's important to intepret them correctly. Maybe you meet a new person on a good day and feel good when talking with them. Do you feel good because the person is pleasant to be with, or because the weather is pleasant? In general, emotions are only used as a source of information when their informational value is not called into question². If you know that you are sad because of something that happened in the morning, and still feel sad when talking to your friend later on, you don't assume that something about your friend is making you feel sad.

People also pay more attention to their feelings when they think them relevant for the question at hand. For example, moods have a larger impact when people are making decisions for themselves rather than others, who may experience things differently. But by default, people tend to assume that their feelings and emotions are "about" whatever it is that they're thinking about at that moment. If they're not given a reason to presume that their emotions are caused by something else than the issue at hand, they don't.²