When it comes to making decisions, Western societies tend to value reason and rational thought. The assumption is that good decisions are based upon careful consideration of all relevant facts. Whenever possible, important factors and potential outcomes should be quantified. The more data-driven the process, the better.
If reason is the foundation of good decision making, emotion is perceived as its enemy. Emotional decisions are seen as impulsive, reactive, and irrational. Emotions are thought to interfere with making good decisions by distorting the salience of particular information, thus creating bias in the decision maker. We are therefore encouraged to set our feelings aside when making decisions, lest they interfere with the process.
Science has started to challenge these assumptions in recent years. There exists a growing body of evidence suggesting that - far from interfering with the decision making process - emotions are an invaluable source of information.
According to Seo and Barrett, there are two factors that determine how emotions influence decision making: how people experience their emotions and what they do with them. The "how" refers to the intensity or strength of a given individual's emotional experiences. "What they do with them" refers to the level of emotional awareness of a given individual and the degree to which his feelings influence his judgment.
This model acknowledges that emotions have the potential to interfere with one's ability to make good decisions; they can influence our perceptions and create bias. As an example: Suppose a person is extremely uncomfortable with risk and uncertainty. He is presented with an investment opportunity that entails a small level of risk over the short term but a strong likelihood of success over the long term. He is uncomfortable with uncertainty; whenever he thinks about the risk associated with this opportunity he becomes anxious. Instead of taking advantage of this opportunity he instead selects a no risk option, even though this selection will earn him less money. His decision to go with the less favorable (and less rational) option is based entirely on his anxiety.
On the other hand, when given a proper role emotions can be an essential part of the decision making process. Research, in fact, suggests that it might be impossible to take emotion out of the equation. One study included participants with impairment in brain areas associated with perception of emotion. When presented with several options and given factual information about each, they found it difficult to develop a preference for any one option over another. As it turns out, preference is, at its core, an emotion. Without emotional input, one cannot develop preferences; it is quite difficult to make decisions without preferences.
In summary, emotions can both facilitate and interfere with good decision making. What do we do with this apparent contradiction? Fortunately, there is a (relatively) simple solution. The key is emotional awareness (mindfulness of emotions). Studies show that the impact of emotional bias on decision making is completely negated when people can recognize their feelings and reflect upon their relevance to the situation at hand.
Using the earlier example, a person could say, "I'm feeling anxious about taking this risk. This is probably because I am uncomfortable with uncertainty; taking risks always makes me anxious. My anxiety is based on habit, not on fact. I will take the risk because it is the better option."
Here's a link to an article that gives some good tips on using emotion in the decision making process: