Humans are evolutionary wired to avoid potentially dangerous situations. Such ability allows us to cope with threatening circumstances, ranging from the encounter of animal predators to speeding cars on the highway. Adaptive as it seems in those situations, individuals may sometimes excessively avoid cues or situations even when a threatening outcome is highly unlikely. People with flight phobia, for example, may refrain from boarding planes out of fear of a potential crash. In such cases, avoidance loses its adaptive role, turning into a maladaptive response that negatively influences an individual's quality of life. The prominent role of avoidance in adaptive and maladaptive functioning makes the study of avoidance learning relevant for both experimental psychologists, who are interested in the underlying psychological mechanisms, as well as clinical psychologists, in their search for tools to counter maladaptive avoidance. The objective of this thesis is two-fold. First, we aim to progress our understanding regarding the psychological mechanisms involved in avoidance learning. Second, we attempt to underline the relevance of the insights gained by laboratory research for clinical practice. For our objective, we completed an extensive literature review on avoidance learning, we conducted a series of experimental studies on avoidance tendencies and risk avoidance, and we presented a novel mathematical model for analyzing approach-avoidance reaction time data. The present thesis gives a fresh view of avoidance learning, as well as effectively translates the laboratory findings to clinical settings.