This Short Review critically evaluates three hypotheses about the effects of emotion on memory: First, emotion usually enhances memory. Second, when emotion does not enhance memory, this can be understood by the magnitude of physiological arousal elicited, with arousal benefiting memory to a point but then having a detrimental influence. Third, when emotion facilitates the processing of information, this also facilitates the retention of that same information. For each of these hypotheses, we summarize the evidence consistent with it, present counter-evidence suggesting boundary conditions for the effect, and discuss the implications for future research. (JINS, 2013, 19, 1–9) LEARNING OBJECTIVES: As a result of reading the article, the learner will be able to: 1) Explain conditions under which emotion does and does not enhance memory 2) Utilize this knowledge to holistically assess the effects of emotion on memory in different populations or when designing or critiquing studies on emotional memory