SARA: A cognitive process model to simulate the anchoring effect and hindsight bias

The cognitive process model "SARA" aims to explain the anchoring effect and hindsight bias by making detailed assumptions about the representation and alteration of item-specific knowledge. The model assumes that all processes, namely generating an estimate, encoding new information (i.e., the "anchor"), and reconstructing a previously generated estimate, are based on a probabilistic sampling process. Sampling probes long-term memory in order to retrieve information into working memory. Retrieval depends on the associative strength between this information and the currently active retrieval cues. Encoding the anchor may alter this associative pattern ("selective activation") or the anchor may serve as a retrieval cue, thus directing memory search ("biased reconstruction"). Both processes lead to systematically changed retrieval probabilities, thus causing the anchoring effect or hindsight bias. The model is completely formalised and implemented as a computer program. A series of simulations demonstrates the power of SARA to reproduce empirical findings and to predict new ones.     

Hindsight bias around the world

Hindsight bias refers to the tendency to overestimate in hindsight what one has known in foresight. Recently, two experiments extended the research to include samples from different cultures (Choi & Nisbett, 2000; Heine & Lehman, 1996). Asking their participants what they would have guessed before they knew the outcome ("hypothetical design"), Choi and Nisbett (2000) found that Koreans, in comparison to North Americans, exhibited more hindsight bias. Heine and Lehman (1996), however, reported that Japanese people in comparison to Canadians showed marginally less hindsight bias. In a second study, in which participants were asked to recall what they had estimated before they knew the outcome ("memory design"), the latter authors found no difference in hindsight bias between Japanese people and Canadians. We extended these studies with 225 Internet participants, in a hypothetical design, from four different continents (Asia, Australia, Europe, and North America). Hindsight bias was large and similar for all samples except for German and Dutch participants who showed no hindsight bias at all. While the latter effect may be based on peculiarities of the material and of the participants, the former underscores the worldwide stability of the phenomenon. In addition a follow-up surprise rating (paper and pencil) in China (35 participants) and Germany (20 participants) revealed that only less surprising items led to hindsight bias while more surprising ones did not. We suggest that the basic cognitive processes leading to hindsight bias are by-products of the evolutionary-evolved capacity of adaptive learning. On top of these basic processes, individual meta-cognitions (e.g., elicited by surprise) or motives (e.g., a self-serving motive) may further moderate the amount of bias, thus explaining the diverging results of Choi and Nisbett (2000), Heine and Lehman (1996), and our own study.     

A retrieval-based approach to eliminating hindsight bias

Individuals exhibit hindsight bias when they are unable to recall their original responses to novel questions after correct answers are provided to them. Prior studies have eliminated hindsight bias by modifying the conditions under which original judgments or correct answers are encoded. Here, we explored whether hindsight bias can be eliminated by manipulating the conditions that hold at retrieval. Our retrieval-based approach predicts that if the conditions at retrieval enable sufficient discrimination of memory representations of original judgments from memory representations of correct answers, then hindsight bias will be reduced or eliminated. Experiment 1 used the standard memory design to replicate the hindsight bias effect in middle-school students. Experiments 2 and 3 modified the retrieval phase of this design, instructing participants beforehand that they would be recalling both their original judgments and the correct answers. As predicted, this enabled participants to form compound retrieval cues that discriminated original judgment traces from correct answer traces, and eliminated hindsight bias. Experiment 4 found that when participants were not instructed beforehand that they would be making both recalls, they did not form discriminating retrieval cues, and hindsight bias returned. These experiments delineate the retrieval conditions that produce—and fail to produce—hindsight bias.     

双向背景信息外部锚问题决策的眼动特征

采用正反双向背景信息日常生活外部锚问题,选取64名大学生,运用眼动技术,考察锚值及双向信息对外部锚问题决策的影响。结果发现：高、低锚组锚定效应指数均在0.76以上,且不存在显著差异。回答锚值比较问题时,从锚值向反向信息的眼跳次数和注视时间显著多于向正向信息的眼跳次数和注视时间。回答估计值问题时,从估计值问题向锚值的眼跳次数和注视时间显著多于向双向信息的眼跳次数和注视时间。研究表明,外部锚引起程度较高的锚定效应。反向信息在问题理解及决策中得到更多关注。锚值在回答锚值比较及估计值问题阶段均对决策产生显著影响。支持了选择通达和信息加工负性偏向观点。     

Hindsight bias as a function of anchor distance and anchor plausibility

This study explored the influence of anchor distance on hindsight bias and how the subjective plausibility of different anchors moderates this relation. In addition to the standard memory design used in hindsight bias research, participants were asked to indicate the range of values for possible answers to difficult almanac questions. Varying anchor distance on the basis of each participant's individual range of possible answers showed (1) that anchor plausibility decreased with increasing anchor distance following a non-linear monotone function, (2) that size of hindsight bias initially increased with increasing anchor distance but, from a certain distance, started to decrease, and (3) that hindsight bias was found to be always higher for plausible than for implausible anchors.     

Hindsight bias as a function of anchor distance and anchor plausibility

This study explored the influence of anchor distance on hindsight bias and how the subjective plausibility of different anchors moderates this relation. In addition to the standard memory design used in hindsight bias research, participants were asked to indicate the range of values for possible answers to difficult almanac questions. Varying anchor distance on the basis of each participant's individual range of possible answers showed (1) that anchor plausibility decreased with increasing anchor distance following a non-linear monotone function, (2) that size of hindsight bias initially increased with increasing anchor distance but, from a certain distance, started to decrease, and (3) that hindsight bias was found to be always higher for plausible than for implausible anchors.     

Associative recognition processes are modulated by the semantic unitizability of memoranda

Although memory of episodic associations is generally considered to be recollective in nature, it has been suggested that when stimuli are experienced as a unit, familiarity processes might contribute to their subsequent associative recognition. To investigate the effect of semantic relatedness during episodic encoding on the processes of retrieval of associative information, we had participants interactively encode pairs of object pictures, vertically arranged so as to suggest a functional or configural relationship between them. Half the pairs were independently judged to be of related objects (e.g., a lamp over a table) and half of unrelated objects (e.g., a key-ring over an apple). At test, participants discriminated between intact, recombined, and new pairs while event related potentials (ERPs) were recorded. In an early ERP marker of retrieval success generally associated with familiarity processes, differences related to associative memory only emerged for related pairs, while differences associated with item memory emerged for both related and unrelated pairs. In contrast, in a later ERP effect associated with recollection, differences related to associative memory emerged for both related and unrelated pairs. These findings may indicate that retrieval of episodic associations formed between two semantically related visual stimuli can be supported by familiarity-related processes.     

Strength of hindsight bias as a consequence of meta-cognitions

Hindsight bias is the tendency of people to falsely believe that they would have correctly predicted the outcome of an event once it is known. The present paper addresses the ongoing debate as to whether the hindsight bias is due to memory impairment or biased reconstruction. The memory impairment approach maintains that outcome information alters the memory trace of the initial judgement, whereas the biased reconstruction approach assumes that people who have forgotten their initial judgements are forced to guess and, in the presence of outcome information, are likely to use this information as an anchor. Whereas the latter approach emphasises the role of meta-cognitive considerations, meta-cognitions are not included in the memory impairment explanation. Two experiments show that the biased reconstruction approach provides a better explanation for empirical findings in hindsight bias research than does the memory impairment explanation.     

Strength of hindsight bias as a consequence of meta-cognitions

Hindsight bias is the tendency of people to falsely believe that they would have correctly predicted the outcome of an event once it is known. The present paper addresses the ongoing debate as to whether the hindsight bias is due to memory impairment or biased reconstruction. The memory impairment approach maintains that outcome information alters the memory trace of the initial judgement, whereas the biased reconstruction approach assumes that people who have forgotten their initial judgements are forced to guess and, in the presence of outcome information, are likely to use this information as an anchor. Whereas the latter approach emphasises the role of meta-cognitive considerations, meta-cognitions are not included in the memory impairment explanation. Two experiments show that the biased reconstruction approach provides a better explanation for empirical findings in hindsight bias research than does the memory impairment explanation.     

Hindsight bias: a by-product of knowledge updating?

With the benefit of feedback about the outcome of an event, people's recalled judgments are typically closer to the outcome of the event than their original judgments were. It has been suggested that this hindsight bias may be due to a reconstruction process of the prior judgment. A model of such a process is proposed that assumes that knowledge is updated after feedback and that reconstruction is based on the updated knowledge. Consistent with the model's predictions, the results of 2 studies show that knowledge after feedback is systematically shifted toward feedback, and that assisting retrieval of the knowledge prior to feedback reduces hindsight bias. In addition, the model accounts for about 75% of cases in which either hindsight bias or reversed hindsight bias occurred. The authors conclude that hindsight bias can be understood as a by-product of an adaptive process, namely the updating of knowledge after feedback.     

Individual Differences in Susceptibility to Misinformation Effects and Hindsight Bias

The present study examined individual differences in susceptibility to two similar forms of memory distortion: the misinformation effect and hindsight bias. The misinformation effect occurs when individuals witness an event, are provided with misinformation, and recall the original event as containing elements of the misinformation. Hindsight bias occurs when individuals make judgments, are provided with feedback, and recall their original judgments as being more similar to the feedback than they actually were. Seventy-five participants completed a misinformation task, a hindsight bias task, and several individual difference measures related to memory distortions. Working memory capacity was negatively correlated with the misinformation effect and hindsight bias, and the misinformation effect and hindsight bias were negatively correlated with one another. Although the misinformation effect and hindsight bias are measured with similar designs, and both are predicted by working memory capacity, the negative correlation between them suggests these phenomena result from somewhat different processes.     

Age-related deficits in associative memory: the influence of impaired strategic retrieval

In 2 experiments, the authors investigated whether impaired strategic retrieval processes contribute to the age-related deficit in associative memory. To do so, they compared older and younger adults on measures of associative memory that place high demands on retrieval processes (associative identification and recall-to-reject) to measures that place low demands on such processes (associative reinstatement and recall-to-accept). Results showed that older adults were severely impaired on associative identification and recall-to-reject measures; relatively intact on recall-to-accept measures, unless recollection was prominent; and intact on associative reinstatement measures. Together, these findings suggest that impairment in strategic retrieval accounts for older adults' deficits in memory for associative information and that this deficit, above and beyond poor binding of items, leads to and amplifies an impairment in overall recollection.     

Individual differences in reverse Hindsight bias: I never thought something like chernobyl would happen. Did I?

Hindsight bias was studied in the context of the accident in the Chernobyl nuclear power plant, which took place on April 26th 1986. An individual difference factor which relates to the motivation to process information, need for cognition, was expected to moderate the occurrence of hindsight bias. Probability estimates of many casualties due to the use of nuclear power in The Netherlands were obtained from 212 individuals two months before the accident in Chernobyl. These estimates were compared with similar estimates made in hindsight by the same individuals five months after the accident. Loglinear Analyses reveal a systematic hindsight bias. However, the direction of the bias was contrary to expectations. In hindsight, individuals gave lower probabilities than they actually did two months before the Chernobyl accident. These results reveal a reverse hindsight bias. As hypothesized, need for cognition moderates hindsight bias: individuals low and medium in need for cognition express a systematic reverse hindsight bias, while individuals high in need for cognition do not. High need for cognition individuals also show higher literal consistency between the two measurements, which supports a memory explanation of the moderating effect of need for cognition.     

Hindsight bias doesn't always come easy: causal models, cognitive effort, and creeping determinism

Creeping determinism, a form of hindsight bias, refers to people's hindsight perceptions of events as being determined or inevitable. This article proposes, on the basis of a causal-model theory of creeping determinism, that the underlying processes are effortful, and hence creeping determinism should disappear when individuals lack the cognitive resources to make sense of an outcome. In Experiments 1 and 2, participants were asked to read a scenario while they were under either low or high processing load. Participants who had the cognitive resources to make sense of the outcome perceived it as more probable and necessary than did participants under high processing load or participants who did not receive outcome information. Experiment 3 was designed to separate 2 postulated subprocesses and showed that the attenuating effect of processing load on hindsight bias is not due to a disruption of the retrieval of potential causal antecedents but to a disruption of their evaluation. Together the 3 experiments show that the processes underlying creeping determinism are effortful, and they highlight the crucial role of causal reasoning in the perception of past events.     

Surprise, defence, or making sense: what removes hindsight bias?

This paper examines predictions concerning the absence of hindsight bias. Some hypothesise that because hindsight bias increases with outcome "surprisingness", only unsurprising outcomes will remove it. Others suggest the opposite-that very surprising outcomes will reduce or reverse the bias. A proposed sense-making model suggests that unexpected outcomes (i.e., initially surprising) invoke greater sensemaking, which typically produces greater hindsight bias. If the process is not successful, however, the bias may be reduced or reversed. Expected outcomes will also produce little hindsight bias, but only because they invoke relatively little sensemaking in the first place. Feelings of surprise arising from sensemaking (i.e., resultant surprise) should be inversely related to hindsight bias. Results of four experiments provide support for the model. A secondary goal was to determine the boundaries of a defensive-processing mechanism also thought to reduce hindsight bias for negative, self-relevant outcomes. Results suggest that a sense of responsibility for the outcome may be necessary for defensive processing to be activated.     

The emergence of words: attentional learning in form and meaning

Children improve at word learning during the 2nd year of life—sometimes dramatically. This fact has suggested a change in mechanism, from associative learning to a more referential form of learning. This article presents an associative exemplar-based model that accounts for the improvement without a change in mechanism. It provides a unified account of children's growing abilities to (a) learn a new word given only 1 or a few training trials ("fast mapping"); (b) acquire words that differ only slightly in phonological form; (c) generalize word meanings preferentially along particular dimensions, such as object shape (the "shape bias"); and (d) learn 2nd labels for already-named objects, despite a persisting resistance to doing so ("mutual exclusivity"). The model explains these improvements in terms of increased attention to relevant aspects of form and meaning, which reduces memory interference. The interaction of associations and reference in word learning is discussed.     

跨领域项目间联结记忆中项目提取和关系提取的分离：一项事件相关电位研究

使用ERPs技术, 探讨跨领域项目间联结记忆中项目提取和关系提取的差异。学习阶段, 系列呈现面孔-事件动词材料, 让被试识记面孔、事件动词以及两者之间的关系; 测验阶段, 要求被试对成对刺激进行“相同”、“重组”或“新”判断。结果发现：提取阶段, 刺激呈现后约200 ms, “相同”、“重组”和“新”3种条件下的ERPs开始出现分离, 存在“相同/新”、“重组/新”和“相同/重组”三类新旧效应。在200~300 ms, “相同/新”和“重组/新”两类新旧效应表现在前额和额区皮层; 在300~500 ms, 这两类新旧效应广泛地分布在从前到后各个脑区皮层; 在500~700 ms, “相同/新”新旧效应出现在额-顶区皮层, 而无“重组/新”新旧效应; 在700~1400 ms, 这两类新旧效应发生在前额和额区皮层; 在上述4个时段, “相同/重组”关系新旧效应都发生在额中-中央-顶区皮层。从这些结果可以推知：跨领域项目间联结再认中, 项目新旧效应和关系新旧效应同时出现, 但是关系提取比项目提取较晚完成; 额中-中央-顶区皮层关系新旧效应反映了对项目间关系的回忆加工; 而700 ms以后, 前额、额区皮层新旧效应可能反映了项目之间关系提取过程的执行加工功能。     

Personality differences in hindsight bias

Ten personality correlates of hindsight bias were tested in a study with 75 participants answering almanac-type knowledge questions. Participants showed hindsight bias when hindsight estimates were compared to foresight estimates (memory condition), when hindsight estimates were compared to foresight estimates of other participants (BS = between-subjects hypothetical condition), and when hindsight estimates were compared to foresight estimates in response to equally difficult control items (WS = within-subject hypothetical condition). The magnitude of hindsight bias in both hypothetical conditions was positively associated with the participant's field dependence and his or her tendency for favourable self-presentation (as measured by social desirability and impression management). Between-subjects hypothetical hindsight was associated with the participant's conscientiousness and need for predictability and control (as measured by a rigidity scale). In a multiple regression analysis, 39% of the variance in BS hypothetical hindsight, 24% of the variance in WS hypothetical hindsight, but no significant proportion of the variance in memory hindsight could be accounted for by personality measures. It is concluded that individual differences in hindsight bias exist and must be taken into account in a complete model of the effect.     

Personality differences in hindsight bias

Ten personality correlates of hindsight bias were tested in a study with 75 participants answering almanac-type knowledge questions. Participants showed hindsight bias when hindsight estimates were compared to foresight estimates (memory condition), when hindsight estimates were compared to foresight estimates of other participants (BS = between-subjects hypothetical condition), and when hindsight estimates were compared to foresight estimates in response to equally difficult control items (WS = within-subject hypothetical condition). The magnitude of hindsight bias in both hypothetical conditions was positively associated with the participant's field dependence and his or her tendency for favourable self-presentation (as measured by social desirability and impression management). Between-subjects hypothetical hindsight was associated with the participant's conscientiousness and need for predictability and control (as measured by a rigidity scale). In a multiple regression analysis, 39% of the variance in BS hypothetical hindsight, 24% of the variance in WS hypothetical hindsight, but no significant proportion of the variance in memory hindsight could be accounted for by personality measures. It is concluded that individual differences in hindsight bias exist and must be taken into account in a complete model of the effect.