Past research has examined how the emotions prompted by an event are related to subsequent memories for that event. For example, flashbulb memory research has shown that the content of seemingly vivid and emotional memories becomes increasingly distorted as retention intervals increase e.g., Neisser & Harsch, 1992). Such research has explored emotion and memory for everyday events Betz & Skowronski, 1997 Thompson, Skowronski, Larsen, & Betz, 1996), memory for extraordinary public events e.g., Conway, 1995), and memory for private traumatic events e.g., Nadel & Jacobs, 1998). However, a related and largely ignored issue concerns the fate of event emotions in memory. Specifi- cally, how might the passage of time be related to the emotions that are evoked when an event is recalled? One theory relevant to this question is Taylor's 1991) mobilisation- minimisation hypothesis. Taylor's hypothesis suggests that the long-term sup- pression of negative affect is a healthy coping mechanism. According to this hypothesis, when a person experiences a negative event, two sets of mechanisms are activated. The first mechanism is the mobilisation of resources: People activate their biological, psychological, and social resources to cope with the immediate consequences of a negative event. Such activation is usually not necessary to cope with a positive event. The second mechanism is minimisation. To return to a state of homeostasis, opponent processes work to dampen the impact of the negative event. As with mobilisation, minimisation occurs bio- logically, cognitively, and socially, and minimisation is usually stronger for negative events than for positive events. When applied to the memory domain, this theory implies that, as time passes, the intensity of emotions associated with negative events should decrease more rapidly than the intensity of emotions associated with positive events. Several studies have provided empirical support for this proposition. For example, participants in a study by Cason 1932) described from three to eight emotional memories from the previous week. These participants then rated the current affect provoked by each memory and the affect associated with the original event. Participants made similar judgements about the same events three weeks later. Cason found that the intensity of the feelings associated with all events became weaker over time. However, this weakening was significantly greater for negative events. Holmes 1970) designed a study to both replicate Cason's 1932) findings and to explore whether this effect could explain why positive events and stimuli tend to be better remembered than negative events for more on this positivity bias, see Matlin & Stang, 1978). Holmes hypothesised that positive events may be better remembered because they retain more of their original affect than negative events. Holmes asked 26 participants to record pleasant and unpleasant events and to record the affect associated with those events. One week later, as part of an event recall task, he again assessed the affect associated with the events. Holmes found that unpleasant events faded in emotional intensity more 704 WALKER ET AL.

than pleasant events, which replicated Cason's results. One additional point to be made about the Holmes' study is that it minimises the possibility that the fading affect bias is caused by retrospective distortions in memory for the affect originally associated with events. This is because the affect initially associated with events was assessed soon after the events occurred. Holmes also found that participants were less likely to recall experiences that decreased in affective intensity compared to experiences that did not decrease in intensity. However, Holmes was unable to provide definitive evidence that the positivity bias was caused by a difference in emotional fading between pleasant and unpleasant events. Suedfeld and Eich 1995) supplied further empirical evidence supporting the existence of a positivity bias in autobiographical memory. In Experiment 2 of this research, participants were presented with 12 common, emotionally neutral probe words and asked to recall memories related to the probes. Participants were asked to rate the intensity of the event at the time the event occurred and at the time of event recall on a 9-point scale ranging from 1 neutral) to 9 extremely intense). Events were rated as being more intense at the time of occurrence than at the time of recall MInitial = 5.76 MCurrent = 3.92). Although Suefeld and Eich did not directly compare the fading of affective intensity for pleasant and unpleasant events, they did report that the average current pleasantness rating of events was slightly positive 0.17 on a +1 to 71 scale), a finding that would be expected if negative affect faded more than positive affect. Recently, a series of studies re-examined this issue using a diary procedure Walker, Vogl, & Thompson, 1997). Walker et al. asked participants to keep a diary of unique daily events. As an event was entered into their diary, partici- pants rated the pleasantness of the events. After a specific retention interval 3 months in Experiment 1 1 year in Experiment 2 and 4.5 years in Experiment 3), participants rated the emotions provoked when they were reminded of each of the recorded events. Participants also rated how well they remembered each event. As in previous research, the affective intensity of events faded over time and the intensity of negative events faded more rapidly than the intensity of positive events. As with the Holmes study, this diary methodology minimises the possibility that these effects are caused by retrospective distortions in memory for the affect originally associated with the event. Examination of the memory ratings suggested that positive events were remembered slightly better than negative events, but the results did not yield a relation between the fading of affective intensity and the memory advantage afforded by positive events. Thus, these findings confirmed the idea that the affect associated with negative events fades more rapidly over time than the affect associated with positive events, and they also suggest that memory for event content and event affect are relatively independent. Taken together, all of these studies suggest that the autobiographical memory system does not treat the negative and positive affect associated with events ON THE EMOTIONS 705

equally. Over time, that system seems to more strongly dampen the affect associated with unpleasant memories than the affect associated with pleasant memories. For ease of discussion, the differential fading of positive and negative emotions will be referred to as the fading affect bias. However, this fading affect bias may not occur in the same way for everyone. For example, one might hypothesise that individuals who are mildly depressed dysphoric) should show a different pattern of fading affect than nondysphoric individuals. The literature already provides evidence that the memories of dysphorics and nondypsphorics differ in several ways. For example, dysphorics typically report less detailed memories than nondysphorics, especially when the recalled events are positive rather than negative e.g., Lyubomirsky, Caldwell, & Nolen-Hoeksema, 1998 Williams & Broadbent, 1986 Williams & Scott, 1988). It is well understood that dysphorics often get caught in a vicious cycle of experiencing negative events and thinking about negative events e.g., Teasdale, 1983). Furthermore, dysphorics report a greater number of negative memories than nondysphorics e.g., Clark & Teasdale, 1982 Lloyd & Lishman, 1975 Reynolds & Salkovskis, 1992). A disparity in the extent to which emotions prompted by event memories fade over time might be yet another difference in the memory systems of dysphorics and nondysphorics. More specifically, we suspect that dysphorics will evince a smaller fading affect bias than non- dysphorics or no bias at all). This may occur because the negative affect associated with the negative memories of dysphorics does not fade as much as the negative affect associated with the negative memories of nondysphorics, or because the positive affect associated with positive memories fades more for dysphorics or both). Regardless of the exact pattern that might emerge, the first goal of the studies presented in the present paper was to find evidence that dysphoria disrupts the fading affect bias. The second goal of the study was to rule out three possible alternative explanations for the fading affect bias. The first explanation suggests that the fading affect bias might be an artifact of event age. That is, in retrospectively recalling autobiographical events, participants might recall older negative events and newer positive events. If this were the case, then the data would give the appearance of a fading affect bias even if the rate of fading were equivalent for negative and positive events. Because the bias also occurs in diary paradigms that automatically control for event age e.g., Holmes, 1970 Walker et al., 1997), this possibility seems unlikely. Nevertheless, in our studies we examined whether recalled event age was related to the magnitude of the fading affect bias. The second alternative explanation lies in the extremity of the initial affect ratings. Participants may have recalled negative events that were more emo- tionally extreme than their recalled positive events. If this were the case, then the data would give the appearance of a fading affect bias. However, the bias might simply be a consequence of the fact that the affect associated with negative 706 WALKER ET AL.