Bite-size: Emotions affect how we think, judge, and make decisions. But emotions also act as a source of information. Positive mood = positive evaluation. That is called the “affect-as-information” hypothesis.
Full-size:
Emotions are powerful and universal drivers of how we make decisions. While predictable, there are many variables one needs to consider. Context is key. So, consider this: emotions are a source of information itself. This is called the “affect as information” hypothesis.
Having a thought usually triggers some feeling, either positive or negative. But that experience of feeling happy or sad can also act as data for further mental processing (and evaluation of some thought or some thing). A classic example is weather: feeling happy on a sunny day can cause you to make more favorable judgments or focus on things that make you feel good. The opposite is true of feeling sad on a cold, grey, rainey day.
A scientific way to say it: The embodied nature of some of these emotional experiences makes the evaluation of analogous beliefs more compelling.
Mood can also influence the level of processing information. Positive emotions tend to lead to wider, big-picture thinking, while negative emotions often lead to a more narrowed, detail-oriented focus.
Here’s how this could work in an ad: A car commercial targeted towards an audience who is predictably in a good mood (e.g., their favorite football team is winning) leads with an upbeat track. The viewer can be predicted to make a more positive judgment about the car brand. But knowing that a positive mood can cause them to think about the car in a global way (30,000 ft level), a commercial that hones in on bigger messaging like, “How does this car serve my family?” will do better than an ad that focuses more on the tech and specs.