In order to test the notion that responses to odors are learned as a function of the emotional context in which they are first perceived directly, we conducted a study in which a novel odor was paired with either a positive or negative emotional experience. We found that after the pairing procedure, ratings given to the test odor varied in accord with the paired emotion; making the odor then perceived as either good or bad, depending upon what paired experience the participant had. One case when olfactory sensory attributes may have an unlearned impact is when odors are irritating (for example, ammonia) and thus discomfort is felt at the same time as odor sensation occurs, which happens when an odor stimulates the trigeminal nerve in addition to eliciting olfactory sensation. Many odors elicit trigeminal stimulation to varying degrees and the subjective distinction between pure odor and trigeminal irritation is not possible to make. These cases explain why you may have had the experience of being immediately repelled by a certain scent. The context in which an odor is encountered can also have a big influence. So if you aren¿t expecting a certain smell in a particular situation you might have a much more negative reaction to it than you otherwise would. For instance, if you think that you are reaching for your wine glass when in reality you sip from your water glass by mistake; you¿ve never had wine from such a bad year!
So now you understand how associative learning produces our odor preferences, but as I stated at the outset it also explains how odors influence our moods and even our behaviors. A number of studies have shown that the odors people like make them feel good, whereas odors people dislike make them feel bad. These mood responses have also been reported physiologically. For example, skin conductance, heart-rate and eye-blink rates in response to various liked or disliked scents coincide with the mood the person is experiencing.
Downstream from how odors influence our moods is the way that moods influence how we think (cognition) and how we act (behavior). In terms of cognition, mood has been shown to influence creativity with the typical finding that people in a positive mood exhibit higher levels of creativity than individuals in a bad mood. Odors can also produce the same effects. When people were exposed to an odor they liked creative problem solving was better than it was when they were exposed to an unpleasant odor condition.
Taking this one step further is the way in which mood influences on thinking are translated into observable behavior. A growing body of literature shows that positive mood is linked to an increase in productivity, performance and the tendency to help others, while negative mood reduces prosocial behavior. Notably, prosocial behavior and productivity are also enhanced in the presence of pleasant ambient odors. For example, people exposed to the smells of baking cookies or roasting coffee were more inclined to help a stranger than people not exposed to an odor manipulation. People who worked in the presence of a pleasant smelling air freshener also reported higher self-efficacy, set higher goals and were more likely to employ efficient work strategies than participants who worked in a no-odor condition. Pleasant ambient odors have also been found to enhance vigilance during a tedious task and improve performance on anagram and word completion tests. Conversely, the presence of a malodor reduced participants¿ subjective judgments and lowered their tolerance for frustration. Participants in these studies also reported concordant mood changes. Thus, the observed behavioral responses are due to the effect that the ambient odors has on people¿s mood.
So there you have it, odors influence mood, work performance, and many other forms of behavior via their learned associations and particularly their learned emotional associations. The next time you smell a scent that you like, see if you can figure out where you first experienced it and then also reflect to yourself whether you feel any mood change and if that mood makes you want to do anything in particular.