People vary in how they perceive emotionally ambiguous events: For example, anxious individuals are particularly likely to interpret emotional ambiguity in a threatening way. Experimental studies have shown that such processing styles are malleable, and when modified can lead to corresponding changes in emotional reactivity. The methods used to modify processing and to assess subsequent changes in emotional reactivity are described and theoretical accounts of the mechanism underlying such changes are discussed. Recent application of related methods to modifying clinical problems demonstrates their utility, but beyond such practical applications, the approach provides new ways of probing the nature of the relationship between cognition and emotion.Suppose you venture an opinion on current events to a group of acquaintances and notice that some of them are smiling. Most of us would take that as a sign of approval, or at least a degree of positive interest. In contrast, people who are prone to feeling anxious in social situations are quite likely to interpret the smiles of others as indicating derision, and feel embarrassed rather than pleased. As this example is intended to illustrate, the interpretation of emotional information sometimes seems to influence how we feel, although it is probably also true that how we feel can influence how we interpret events. In the present paper, after a brief and necessarily selective review of the evidence for such an association, experiments are described that support the hypothesis of a causal relationship between how ambiguous information is interpreted and emotional reactivity, and that suggest mechanisms that may underlie this relationship.The methods used to investigate this relationship open up new ways of studying cognitionÁemotion interactions, as well as new approaches for treating or preventing emotional problems.