Causal judgement from contingency information: Judging interactions between two causal candidates

In two experiments participants judged the extent to which occurrences and non-occurrences of an effect could be attributed to an interaction between two causal candidates A and B. In Experiment 1 judgements were influenced by the proportion of instances normatively evaluated as confirmatory for the interaction interpretation, when the objective contingency was held constant. Information about instances in which both candidates were present and the effect occurred was more influential than information about instances in which both candidates were absent and the effect did not occur. In Experiment 2 the occurrence rate of the effect when both candidates were present, when A alone was present, when B alone was present, and when both were absent was manipulated. Interaction judgements were mainly determined by occurrence rate when both were present. There was also a significant effect of occurrence rate when both were absent, but the other two occurrence rates had no significant effect. These results are interpreted as supporting a general model in which causal judgements are made according to the proportion of instances evaluated as supporting the interpretation being judged.     

Inferences about unobserved causes in human contingency learning

Estimates of the causal efficacy of an event need to take into account the possible presence and influence of other unobserved causes that might have contributed to the occurrence of the effect. Current theoretical approaches deal differently with this problem. Associative theories assume that at least one unobserved cause is always present. In contrast, causal Bayes net theories (including Power PC theory) hypothesize that unobserved causes may be present or absent. These theories generally assume independence of different causes of the same event, which greatly simplifies modelling learning and inference. In two experiments participants were requested to learn about the causal relation between a single cause and an effect by observing their co-occurrence (Experiment 1) or by actively intervening in the cause (Experiment 2). Participants' assumptions about the presence of an unobserved cause were assessed either after each learning trial or at the end of the learning phase. The results show an interesting dissociation. Whereas there was a tendency to assume interdependence of the causes in the online judgements during learning, the final judgements tended to be more in the direction of an independence assumption. Possible explanations and implications of these findings are discussed.     

Belief-based and covariation-based cues affect causal discounting.

Causal discounting occurs when the perceived efficacy of a putative cause is reduced by the presence of a stronger causal candidate. Previous studies of causal discounting have defined the strength of causal candidates in terms of the degree to which the cause and the effect covary (e.g., Baker, Mercier, Vallee-Tourangeau, Frank, & Pan, 1993). In contrast, in the present study, causal strength was defined in terms of both covariation- and belief-based cues. Seventy-two participants made causality judgments for a fictional causal candidate both in isolation and when paired with either a stronger or a weaker cause. The results demonstrated that the degree to which a causal candidate is discounted depends not only on the degree to which an alternative cause covaries with the effect, but also on whether the alternative is a believable or unbelievable candidate. Indeed, it was observed that a highly believable alternative will produce the discounting effect, even if it is a weaker covariate than the original candidate. These findings suggest the need to incorporate both belief-based and covariation-based cues into models of causal attribution.     

Judging the Importance of Constant and Variable Candidate Causes: A Test of the Power PC Theory

In two causal induction experiments subjects rated the importance of pairs of candidate causes in the production of a target effect; one candidate was present on every trial (constant cause), whereas the other was present on only some trials (variable cause). The design of both experiments consisted of a factorial combination of two values of the variable cause's covariation with the effect and three levels of the base rate of the effect. Judgements of the constant cause were inversely proportional to the level of covariation of the variable cause but were proportional to the base rate of the effect. The judgements were consistent with the predictions derived from the Rescorla-Wagner (1972) model of associative learning and with the predictions of the causal power theory of the probabilistic contrast model (Cheng, 1997) or 'power PC theory'. However, judgements of the importance of the variable candidate cause were proportional to the base rate of the effect, a phenomenon that is in some cases anticipated by the power PC theory. An alternative associative model, Pearce's (1987) similaritybased generalization model, predicts the influence of the base rate of the effect on the estimates of both the constant and the variable cause.     

Recognition memory for pictorial material in subclinical depression

Depression has been associated with impaired recollection of episodic details in tests of recognition memory that use verbal material. In two experiments, the remember/know procedure was employed to investigate the effects of dysphoric mood on recognition memory for pictorial materials that may not be subject to the same processing limitations found for verbal materials in depression. In Experiment 1, where the recognition test took place two weeks after encoding, subclinically depressed participants reported fewer know judgements which were likely to be at least partly due to a remember-to-know shift. Although pictures were accompanied by negative or neutral captions at encoding, no effect of captions on recognition memory was observed. In Experiment 2, where the recognition test occurred soon after viewing the pictures, subclinically depressed participants reported fewer remember judgements. All participants reported more remember judgements for pictures of emotionally negative content than pictures of neutral content. Together, these findings demonstrate that recognition memory for pictorial stimuli is compromised in dysphoric individuals in a way that is consistent with a recollection deficit for episodic detail and also reminiscent of that previously reported for verbal materials. These findings contribute to our developing understanding of how mood and memory interact.     

Discounting in causality and covariation judgements

In two experiments, humans were asked to judge the strength of a moderate contingency between a cue and an outcome in the presence of a second strong contingency between another cue and the outcome. The first experiment replicated the discounting effect whereby a strong contingency causes subjects to reduce or discount judgements of a moderate contingency. This experiment used a video-game procedure in which subjects camouflaged a tank to make it safe from mines. The second causal cue was the presence or absence of a spotter plane. Experiment 1 also ruled out the possibility that judgements might be determined by the number of co-occurrences of the cue and outcome as opposed to the level of contingency. The second experiment used an abstract scenario in which discounting was demonstrated when subjects were asked to judge the relationship between the occurrence of geometric objects. The instructions were neutral to discourage causal hypotheses. These results support the notion that judgements result from associative or connectionist processes and not from a two-step cognitive retrospective process in which an estimate of covariation is calculated between cue and outcome and then in a second step this information is used in a normative manner when a decision is made.     

Perceptual learning in humans: Roles of preexposure schedule, feedback, and discrimination assay

In three experiments, humans received preexposure to two compound flavours (AX and BX: saline-lemon and sucrose-lemon) that were presented either in an intermixed (e.g., AX, BX, . . . BX, AX, . . .) or a blocked (e.g., AX, AX, . . . BX, BX. . .) fashion. Subsequently, AXwas paired with an unpleasant bitter taste, and the discriminability of AX and BX was assessed using the accuracy of same/different judgements and by the extent to which any learned dislike of AX generalized to BX. When participants received feedback about the accuracy of their same/different judgements during preexposure those given intermixed preexposure were more accurate in making these judgements during the test than those given blocked preexposure (Experiments 1 and 2A), however, there was no evidence of any learned dislike in these experiments. In Experiment 2B, in which participants did not receive feedback about the accuracy of their judgements, there was no effect of the preexposure regime on same/different judgements, but there was a learned dislike of AX, and this generalized less to BX in participants given intermixed than in those given blocked preexposure. The beneficial effects of intermixed preexposure are consistent with results from other species (chicks and rats), but the differences created by the presence or absence of feedback place constraints on the analysis of these effects.     

Strategy selection in causal reasoning: when beliefs and covariation collide.

The present study investigated how people combine covariation information (Cheng & Novick, 1990, 1992) with pre-existing beliefs (White, 1989) when evaluating causal hypotheses. Three experiments, using both within- and between-subjects designs, found that the use of covariation information and beliefs interacted, such that the effects of covariation were larger when people assessed hypotheses about believable than about unbelievable causal candidates. In Experiment 2, this interaction was observed when participants made judgments in stages (e.g., first evaluating covariation information about a causal candidate and then evaluating the believability of a candidate), as well as when the information was presented simultaneously. Experiment 3 demonstrated that this pattern was also reflected in participants' metacognitive judgments: Participants indicated that they weighed covariation information more heavily for believable than unbelievable candidates. Finally, Experiments 1 and 2 demonstrated the presence of individual differences in the use of covariation- and belief-based cues. That is, individuals who tended to base their causality judgments primarily on belief were less likely to make use of covariation information and vice versa. The findings were most consistent with White's (1989) causal power theory, which suggests that covariation information is more likely to be considered relevant to believable than unbelievable causes.     

Asymptotic judgment of cause in a relative validity paradigm

We report three experiments in which we tested asymptotic and dynamic predictions of the Rescorla-Wagner (R-W) model and the asymptotic predictions of Cheng's probabilistic contrast model (PCM) concerning judgments of causality when there are two possible causal candidates. We used a paradigm in which the presence of a causal candidate that is highly correlated with an effect influences judgments of a second, moderately correlated or uncorrelated cause. In Experiment 1, which involved a moderate outcome density, judgments of a moderately positive cause were attenuated when it was paired with either a perfect positive or perfect negative cause. This attenuation was robust over a large set of trials but was greater when the strong predictor was positive. In Experiment 2, in which there was a low overall density of outcomes, judgments of a moderately correlated positive cause were elevated when this cause was paired with a perfect negative causal candidate. This elevation was also quite robust over a large set of trials. In Experiment 3, estimates of the strength of a causal candidate that was uncorrelated with the outcome were reduced when it was paired with a perfect cause. The predictions of three theoretical models of causal judgments are considered. Both the R-W model and Cheng's PCM accounted for some but not all aspects of the data. Pearce's model of stimulus generalization accounts for a greater proportion of the data.     

Primacy Effect in Credibility Judgements: The Vulnerability of Verbal Cues to Biased Interpretations

We explored the vulnerability of credibility judgements of written accounts (mediated by their richness in details) to primacy effect. Specifically, we examined whether the order by which two texts were presented affected their credibility judgements. In Experiment 1, participants read two life stories of the same narrator, one rich and the other poor in details, while their presentation order was manipulated. Results showed that participants tended to believe the narrator more when the rich story preceded the poor story than when the presentation order was reversed. In Experiment 2, the richness‐order was manipulated within a single story, and its results revealed that, although participants read stories of equal length, they perceived a story that began in a rich manner as richer than a story that began in a poor manner. Together, results point to the vulnerability of the ‘richness in detail’ indicator to judgemental biases. Copyright © 2013 John Wiley & Sons, Ltd.     

Remembrance of remembrance past

Arnold and Lindsay (2002) found that individuals more often failed to remember they had previously recalled an item if that item had been cued in a qualitatively different way on two recall occasions: the “forgot-it-all-along” (FIA) effect. Experiment 1 was designed to determine if the FIA effect arises because participants incorrectly believe they have not been previously tested for an item, or because they incorrectly believe they have failed to recall the item when previously tested. Experiment 2 measured participants' confidence in their incorrect prior-recall judgements, and Experiment 3 tested participants' ability to “recover” their previous recollection when the prior-recall context was restored. Results indicated that participants usually believed they had not previously been cued for the items they failed to remember previously recalling; they were often confident in their incorrect judgements of prior non-remembering; and re-introducing the context of prior remembering sometimes enabled them to recapture their memories of previous recall.     

Judgement of two causal candidates from contingency information: II. Effects of information about one cause on judgements of the other cause

When judgements are being made about two causes there are eight possible kinds of contingency information: occurrences and nonoccurrences of the outcome when both causes are present, when Cause 1 alone is present, when Cause 2 alone is present, and when neither cause is present. It is proposed that contingency information is used to some extent to judge proportionate strength, which is the proportion of occurrences of the outcome that each cause can account for. This leads to a prediction that judgements of one cause will be influenced by information about occurrences, but not nonoccurrences, of the outcome when only the other cause is present. In six experiments consistent support was found for this prediction when the cause being judged had a positive relation with the outcome, but no consistent tendency was found when the cause being judged had a negative relation with the outcome. The effects found for causes with positive contingency cannot be explained by the Rescorla-Wagner model of causal judgement nor by the hypothesis that causal judgements are based on conditional contingencies.     

Remembrance of remembrance past

Arnold and Lindsay (2002) found that individuals more often failed to remember they had previously recalled an item if that item had been cued in a qualitatively different way on two recall occasions: the "forgot-it-all-along" (FIA) effect. Experiment 1 was designed to determine if the FIA effect arises because participants incorrectly believe they have not been previously tested for an item, or because they incorrectly believe they have failed to recall the item when previously tested. Experiment 2 measured participants' confidence in their incorrect prior-recall judgements, and Experiment 3 tested participants' ability to "recover" their previous recollection when the prior-recall context was restored. Results indicated that participants usually believed they had not previously been cued for the items they failed to remember previously recalling; they were often confident in their incorrect judgements of prior non-remembering; and re-introducing the context of prior remembering sometimes enabled them to recapture their memories of previous recall.     

Forward and backward blocking in human contingency judgement

Three experiments investigated whether a process akin to Kamin's (1969) blocking effect would occur with human contingency judgements in the context of a video game. Subjects were presented with sets of trials on each of which they could perform a particular action and observe whether the action produced a particular outcome in a situation in which there was an alternative potential cause of the outcome. In Experiment 1 it was found that prior observation of the relationship between the alternative cause and the outcome did indeed block or reduce learning about the subsequent action-outcome relationship. However, exposure to the relationship between the alternative cause and the outcome after observing the association between the action and the outcome also reduced judgements of the action-outcome contingency (backward blocking), a finding at variance with conditioning theory. In Experiment 2 it was found that, just as is the case with forward blocking, the degree of backward blocking depended on how good a predictor of the outcome the alternative cause was. Finally, in Experiment 3 it was shown that the backward blocking effect was not the result of greater forgetting about the action-outcome relationship in the experimental than in the control condition. These results cast doubt upon the applicability of contemporary theories of conditioning to human contingency judgement.     

These two are different. Yes,they’re the same: Choice blindness for facial identity

We examined the manipulability of face identity judgements by combining a sorting task for unfamiliar faces with a standard test of choice blindness. In Experiment 1, 50 participants completed a sorting task and then justified grouping specific pairs of photos together or apart. On manipulated trials, the presented pairings were different from those the participants had actually produced. Detection rates for these identity manipulations were strikingly low (∼21%). Moreover, participants readily provided justifications for identity decisions that they had not made, typically referring to specific facial features. Experiment 2 was conducted along similar lines and confirmed that lower task difficulty and higher confidence in one’s face identity judgements increase detection rates. We conclude that observers can easily be led to believe that they made identity judgements they did not make. As well as underscoring the fragility of unfamiliar face matching, our findings have implications for identity judgements in legal settings.     

Second-order conditioning in human predictive judgements when there is little time to think

Associative accounts uniquely predict that second-order conditioning might be observed in human predictive judgements. Such an effect was found for cue X in two experiments in which participants were required to predict the outcomes of a series of training trials that included P + and PX-, but only when training was paced by requiring participants to make a prediction within 3 s on each trial. In Experiment 1 training on P + ended before training was given on PX - . In Experiment 2 trials with P+, PX-, T + and other cues were intermixed. In the unpaced group inhibitory learning was revealed by a summation test, TX versus TM, where M was a control stimulus. These results suggest either that pacing interferes with learning successive associations more than with learning simultaneous associations or that lack of time to think interferes with inferential processes required for this type of inhibitory learning.     

Remembering is in the details: Effects of test-list context on memory for an event

We examined how recognition judgements for a set of event details are influenced by the relative difficulty of the other details included on the test. Participants viewed a crime event and then assigned remember/know judgements to details on a recognition test. In Experiment 1, details of medium difficulty were more likely to be classified as remembered when mixed with hard details rather than easy details. Similarly, in Experiment 2, medium details presented in blocked format were more likely to be classified as remembered when preceded by a block of hard details rather than a block of easy details. The test-list context thus appears to influence how participants define remembering. In Experiment 3, informing participants of the relative difficulty of the upcoming block of details eliminated the blocking effect. Implications for accounts of remember/know judgements and for conducting memory interviews are discussed.     

Remembering is in the details: effects of test-list context on memory for an event

We examined how recognition judgements for a set of event details are influenced by the relative difficulty of the other details included on the test. Participants viewed a crime event and then assigned remember/know judgements to details on a recognition test. In Experiment 1, details of medium difficulty were more likely to be classified as remembered when mixed with hard details rather than easy details. Similarly, in Experiment 2, medium details presented in blocked format were more likely to be classified as remembered when preceded by a block of hard details rather than a block of easy details.The test-list context thus appears to influence how participants define remembering. In Experiment 3, informing participants of the relative difficulty of the upcoming block of details eliminated the blocking effect. Implications for accounts of remember/know judgements and for conducting memory interviews are discussed.     

Selecting explanations from causal chains: Do statistical principles explain preferences for voluntary causes?

We investigate whether people prefer voluntary causes to physical causes in unfolding causal chains and whether statistical (covariation, sufficiency) principles can predict how people select explanations. Experiment 1 shows that while people tend to prefer a proximal (more recent) cause in chains of unfolding physical events, causality is traced through the proximal cause to an underlying distal (less recent) cause when that cause is a human action. Experiment 2 shows that causal preference is more strongly correlated with judgements of sufficiency and conditionalised sufficiency than with covariation or conditionalised covariation. In addition, sufficiency judgements are partial mediators of the effect of type of distal cause (voluntary or physical) on causal preference. The preference for voluntary causes to physical causes corroborates findings from social psychology, cognitive neuroscience and jurisprudence that emphasise the primacy of intentions in causal attribution processes. Copyright © 2009 John Wiley & Sons, Ltd.     

Moderators of Candidate Name‐Order Effects in Elections: An Experiment

Past studies of elections have shown that candidates whose names were listed at the beginning of a list on a ballot often received more votes by virtue of their position. This article tests speculations about the cognitive mechanisms that might be responsible for producing the effect. In an experiment embedded in a large national Internet survey, participants read about the issue positions of two hypothetical candidates and voted for one of them in a simulated election in which candidate name order was varied. The expected effect of position appeared and was strongest (1) when participants had less information about the candidates on which to base their choices, (2) when participants felt more ambivalent about their choices, (3) among participants with more limited cognitive skills, and (4) among participants who devoted less effort to the candidate evaluation process. The name‐order effect was greater among left‐handed people when the candidate names were arrayed horizontally, but there was no difference between left‐ and right‐handed people when the names were arrayed vertically. These results reinforce some broad theoretical accounts of the cognitive process that yield name‐order effects in elections.