Age Differences in Processes Underlying Hindsight Bias: A Life-Span Study

Emotional aftermath of the 2020 U.S. presidential election: a study of hindsight bias in younger and older adults

Hindsight bias - also known as the knew-it-all-along effect - is a ubiquitous judgment error affecting decision makers. Hindsight bias has been shown to vary across age groups and as a function of contextual factors, such as the decision maker's emotional state. Despite theoretical reasons why emotions might have a stronger impact on hindsight bias in older than in younger adults, age differences in hindsight bias for emotional events remain relatively underexplored. We examined emotion and hindsight bias in younger and older adults (N = 272) against the backdrop of the 2020 U.S. presidential election. Participants predicted electoral college votes for the two presidential candidates before the election and were asked to remember their predictions approximately three weeks later, after the election results had been finalised. Republicans, for whom the electoral outcome was negatively tinged, exhibited greater hindsight bias for President Biden's result compared with Democrats, for whom the electoral outcome was positive. The asymmetry in hindsight bias between Republicans and Democrats was similar for younger and older participants. This study suggests that negative emotions may exacerbate hindsight bias, and that adult age differences in hindsight bias observed in laboratory settings may not translate to real-world contexts.

The function of REM and NREM sleep on memory distortion and consolidation

During rapid eye movement (REM) sleep, newly consolidated memories can be distorted to adjust the existing memory base in memory integration. However, only a few studies have demonstrated the role of REM sleep in memory distortion. The present study aims to clarify the role of REM sleep in the facilitation of memory distortion, that is, hindsight bias, compared to non-rapid eye movement (NREM) sleep and wake states. The split-night paradigm was used to segregate REM and NREM sleep. The hypotheses are (1) hindsight bias-memory distortion-is more substantial during REM-rich sleep (late-night sleep) than during NREM-rich sleep (early-night sleep); (2) memory stabilization is more substantial during NREM-rich sleep (early-night sleep) than during REM-rich sleep (late-night sleep); and (3) memory distortion takes longer time than memory stabilization. The results of the hindsight bias test show that more memory distortions were observed after the REM condition in comparison to the NREM condition. Contrary to the hindsight bias, the correct response in the word-pair association test was observed more in the NREM than in the REM condition. The difference in the hindsight bias index between the REM and NREM conditions was identified only one week later. Comparatively, the difference in correct responses in the word-pair association task between the conditions appeared three hours later and one week later. The present study found that (1) memory distortion occurs more during REM-rich sleep than during NREM-rich sleep, while memory stabilization occurs more during NREM-rich sleep than during REM-rich sleep. Moreover, (2) the newly encoded memory could be stabilized immediately after encoding, but memory distortion occurs over several days. These results suggest that the roles of NREM and REM sleep in memory processes could be different.

Age-Related Differences in Moral Judgment: The Role of Probability Judgments

Research suggests that moral evaluations change during adulthood. Older adults (75+) tend to judge accidentally harmful acts more severely than younger adults do, and this age-related difference is in part due to the greater negligence older adults attribute to the accidental harmdoers. Across two studies (N = 254), we find support for this claim and report the novel discovery that older adults' increased attribution of negligence, in turn, is associated with a higher perceived likelihood that the accident would occur. We propose that, because older adults perceive accidents as more likely than younger adults do, they condemn the agents and their actions more and even infer that the agents' omission to exercise due care is intentional. These findings refine our understanding of the cognitive processes underpinning moral judgment in older adulthood and highlight the role of subjective probability judgments in negligence attribution.

Memory load of information encoded amplifies the magnitude of hindsight bias

Our recollections tend to become more similar to the correct information when we recollect an initial response using the correct information, known as the hindsight bias. This study investigated the effect of memory load of information encoded on the hindsight bias's magnitude. We assigned participants (N = 63) to either LOW or HIGH conditions, in which they answered 20 or 50 questions, which were their initial responses. Then, they memorized and remembered the correct information. They finally recollected the initial responses. Twenty of the fifty questions in the HIGH condition were identical to those in the LOW condition. We used the answers to these 20 common questions in LOW and HIGH conditions to examine the effect of the memory load of information encoded, defined as the number of correct answers to remember (i.e., 20 or 50) on the hindsight bias. Results indicated that the magnitude of the hindsight bias was more prominent in the HIGH than the LOW condition, suggesting that the memory load amplifies the hindsight bias's magnitude. This finding also implies that controlling the memory load of information encoded when learning correct information could mitigate the hindsight bias. We expect these findings to have practical implications in occupational settings where hindsight bias could lead to critical errors such as financial losses or medical problems.

Hindsight bias in metamemory: outcome knowledge influences the recollection of judgments of learning

Hindsight bias describes people's tendency to overestimate how accurately they have predicted an event's outcome after obtaining knowledge about it. Outcome knowledge has been shown to influence various forms of judgments, but it is unclear whether outcome knowledge also produces a hindsight bias on Judgments of Learning (JOLs). Three experiments tested whether people overestimated the accuracy of their memory predictions after obtaining knowledge about their actual memory performance. In all experiments, participants studied 60 cue-target word pairs, made a JOL for each word pair, and tried to recall the targets in a cued-recall test. In Experiments 1a and 1b, people recollected their original JOLs after attempting to recall each target, that is, after they obtained outcome knowledge for all items. In Experiments 2 and 3, people recollected their original JOLs in a separate phase after attempting to recall half the targets so that they had outcome knowledge for some but not all items. In all experiments, recollected JOLs were closer to actual memory performance than original JOLs for items with outcome knowledge only. Thus, outcome knowledge produced a hindsight bias on JOLs. Our results demonstrate that people overestimate the accuracy of their memory predictions in hindsight.

Hindsight Bias and Electoral Outcomes: Satisfaction Counts More Than Winner-Loser Status

The tendency to perceive outcomes as more foreseeable once they are available is a well-known phenomenon. However, research on the cognitive and motivational factors that induce individuals to overestimate the foreseeability of an electoral outcome has yielded inconsistent findings. In three studies based on large-scale electoral surveys (ITANES, Italian National Election Studies), we argued that the tendency to perceive an electoral outcome as foreseeable is positively and consistently associated with satisfaction with the outcome. Across all studies, satisfaction with the outcome was significantly and positively associated with retrospective foreseeability, above and beyond voters’ preference for a “winning” or “losing” party. In Study 3, a measure of memory distortion of pre-electoral forecasts was included, which was only weakly associated with retrospective foreseeability, but not with satisfaction for the outcome, supporting the notion of different levels of hindsight bias associated with different cognitive and motivational factors.

Only Familiar Information is a "Curse": Children's Ability to Predict What Their Peers Know

The ability to make inferences about what one's peers know is critical for social interaction and communication. Three experiments (n = 309) examined the curse of knowledge, the tendency to be biased by one's knowledge when reasoning about others' knowledge, in children's estimates of their peers' knowledge. Four- to 7-year-olds were taught the answers to factual questions and estimated how many peers would know the answers. When children learned familiar answers, they showed a curse of knowledge in their peer estimates. But, when children learned unfamiliar answers to the same questions, they did not show a curse of knowledge. These data shed light on the mechanisms underlying perspective taking, supporting a fluency misattribution account of the curse of knowledge.

Fluency misattribution and auditory hindsight bias

We conducted three experiments to test the fluency-misattribution account of auditory hindsight bias. According to this account, prior exposure to a clearly presented auditory stimulus produces fluent (improved) processing of a distorted version of that stimulus, which results in participants mistakenly rating that item as easy to identify. In all experiments, participants in an exposure phase heard clearly spoken words zero, one, three, or six times. In the test phase, we examined auditory hindsight bias by manipulating whether participants heard a clear version of a target word just prior to hearing the distorted version of that word. Participants then estimated the ability of naïve peers to identify the distorted word. Auditory hindsight bias and the number of priming presentations during the exposure phase interacted underadditively in their prediction of participants' estimates: When no clear version of the target word appeared prior to the distorted version of that word in the test phase, participants identified target words more often the more frequently they heard the clear word in the exposure phase. Conversely, hearing a clear version of the target word at test produced similar estimates, regardless of the number of times participants heard clear versions of those words during the exposure phase. As per Roberts and Sternberg's (Attention and Performance XIV, pp. 611-653, 1993) additive factors logic, this finding suggests that both auditory hindsight bias and repetition priming contribute to a common process, which we propose involves a misattribution of processing fluency. We conclude that misattribution of fluency accounts for auditory hindsight bias.