Remembering the truth or falsity of advertising claims: A preregistered model-based test of three competing theoretical accounts.

Given the large amount of information that people process daily, it is important to understand memory for the truth and falsity of information. The most prominent theoretical models in this regard are the Cartesian model and the Spinozan model. The former assumes that both "true" and "false" tags may be added to the memory representation of encoded information; the latter assumes that only falsity is tagged. In the present work, we contrasted these two models with an expectation-violation model hypothesizing that truth or falsity tags are assigned when expectations about truth or falsity must be revised in light of new information. An interesting implication of the expectation-violation model is that a context with predominantly false information leads to the tagging of truth whereas a context with predominantly true information leads to the tagging of falsity. To test the three theoretical models against each other, veracity expectations were manipulated between participants by varying the base rates of allegedly true and false advertising claims. Memory for the veracity of these claims was assessed using a model-based analysis. To increase methodological rigor and transparency in the specification of the measurement model, we preregistered, a priori, the details of the model-based analysis test. Despite a large sample size (N = 208), memory for truth and falsity did not differ, regardless of the base rates of true and false claims. The results thus support the Cartesian model and provide evidence against the Spinozan model and the expectation-violation model.

In Colore Veritas? Color effects on the speed and accuracy of true/false responses.

In addition to their perceptual or aesthetic function, colors often carry conceptual meaning. In quizzes, for instance, true and false answers are typically marked in green and red. In three experiments, we used a Stroop task to investigate automatic green-true associations and red-false associations, respectively. In Experiments 1 and 2, stimuli were true statements (e.g., "tables are furniture") and false statements (e.g., "bananas are buildings") that were displayed in different combination of green, red, and gray depending on the experimental condition. In Experiment 3, we used true-related and false-related words shown in green, red, or gray. Participants had to indicate the validity (or semantic meaning) of each statement (or word) as fast and as accurately as possible. We expected that participants would perform best when they had to categorize green stimuli as "true" and red stimuli as "false". The prediction was only confirmed when green and red stimuli were presented within the same context (i.e., same experimental condition). This finding supports the dimension-specificity hypothesis which states that cross-modal associations (here: associations between color and validity) depend on the context (here: the color-context). Moreover, the observed color-validity effects were stronger when participants had to categorize single words instead of sentences and when they had to provide speeded responses. Taken together, these results suggest that controlled processing counteracts the influence of automatic color associations on true/false responses.

The truth revisited: Bayesian analysis of individual differences in the truth effect.

The repetition-induced truth effect refers to a phenomenon where people rate repeated statements as more likely true than novel statements. In this paper, we document qualitative individual differences in the effect. While the overwhelming majority of participants display the usual positive truth effect, a minority are the opposite-they reliably discount the validity of repeated statements, what we refer to as negative truth effect. We examine eight truth-effect data sets where individual-level data are curated. These sets are composed of 1105 individuals performing 38,904 judgments. Through Bayes factor model comparison, we show that reliable negative truth effects occur in five of the eight data sets. The negative truth effect is informative because it seems unreasonable that the mechanisms mediating the positive truth effect are the same that lead to a discounting of repeated statements' validity. Moreover, the presence of qualitative differences motivates a different type of analysis of individual differences based on ordinal (i.e., Which sign does the effect have?) rather than metric measures. To our knowledge, this paper reports the first such reliable qualitative differences in a cognitive task.

Perceived truth of statements and simulated social media postings: an experimental investigation of source credibility, repeated exposure, and presentation format.

To better understand the spread of fake news in the Internet age, it is important to uncover the variables that influence the perceived truth of information. Although previous research identified several reliable predictors of truth judgments-such as source credibility, repeated information exposure, and presentation format-little is known about their simultaneous effects. In a series of four experiments, we investigated how the abovementioned factors jointly affect the perceived truth of statements (Experiments 1 and 2) and simulated social media postings (Experiments 3 and 4). Experiment 1 explored the role of source credibility (high vs. low vs. no source information) and presentation format (with vs. without a picture). In Experiments 2 and 3, we additionally manipulated repeated exposure (yes vs. no). Finally, Experiment 4 examined the role of source credibility (high vs. low) and type of repetition (congruent vs. incongruent vs. no repetition) in further detail. In sum, we found no effect of presentation format on truth judgments, but strong, additive effects of source credibility and repetition. Truth judgments were higher for information presented by credible sources than non-credible sources and information without sources. Moreover, congruent (i.e., verbatim) repetition increased perceived truth whereas semantically incongruent repetition decreased perceived truth, irrespectively of the source. Our findings show that people do not rely on a single judgment cue when evaluating a statement's truth but take source credibility and their meta-cognitive feelings into account.

How explicit warnings reduce the truth effect: A multinomial modeling approach.

The finding that repeating a statement typically increases its perceived truth has been referred to as the truth effect. Previous research has found that warning participants about the truth effect can successfully reduce, but not eliminate the effect. We used a multinomial modeling approach to investigate how warnings affect the cognitive processes that are assumed to underlie judgments of truth. In a laboratory experiment (N = 167), half of the participants were warned about the truth effect before judging the truth of repeated and new statements. Importantly, whereas half of the presented statements were of relatively unknown validity, participants could likely identify the correct truth status for the other half of the statements by drawing on stored knowledge. Multinomial modeling analyses revealed that warning instructions did not affect the retrieval of knowledge or participants' guessing behavior relative to a control condition. Instead, warned participants exhibited a significantly reduced tendency to rely on experiential information such as processing fluency when judging a repeated statement's truth. However, this was only the case for statements for which participants held relevant knowledge. These results are consistent with the notion that it is possible to discount metacognitive experiences such as processing ease when their informational value is questioned. Specifically, our findings suggest that people are less likely to base their judgments of truth on experiential information and metacognitive experiences induced by repetition if (a) they are warned about the deceptive power of repetition, and (b) other valid cues are available to inform their judgments.

Easy on the mind, easy on the wrongdoer? No evidence for perceptual fluency effects on moral wrongness ratings.

Processing fluency-the subjective ease of information processing-influences a variety of judgments (e.g., judgments of familiarity, liking, and truth). A study by Laham, Alter, and Goodwin (2009) suggests that this is also true for moral judgments. More specifically, the authors found that discrepant perceptual fluency mitigates moral wrongness ratings. In five studies (total N = 694), we tested the replicability of this finding for different kinds of scenarios (moral versus conventional transgressions) and different perceptual fluency manipulations. In Studies 1a and 1b we manipulated fluency by text background, in Studies 2a and 2b by font type, and in Study 3 by word spaces. Critically, none of the studies replicated Laham et al.'s discrepant fluency effect on moral wrongness ratings. In turn, we found that moral wrongness ratings were strongly affected by participants' emotional responses to the scenarios. Taken together, the findings of our five studies cast very strong doubt on perceptual fluency effects on moral judgments.

Bald and Bad?

According to (a) the beauty ideal of a full head of hair and (b) the physical attractiveness stereotype (PAS; "what is beautiful is good"), bald men should appear less attractive than nonbald men, not only physically but also socially. To explain inconsistent results on this prediction in previous research, we suggest two antagonistic processes: the automatic activation of the PAS at the implicit level and its suppression at the explicit level, the latter process selectively triggered by individuating information about the target person. In line with this account, we only found negative social attractiveness ratings for bald men by same-aged women when individuating target information was lacking (Experiment 1). In contrast, irrespective of whether individuating information was available or not, we reliably found evidence for the PAS in different implicit paradigms (the implicit association test in Experiment 2 and a source monitoring task in Experiment 3). We conclude that individuating information about bald men suppresses PAS application, but not PAS activation.

More evidence against the Spinozan model: Cognitive load diminishes memory for "true" feedback.

We tested two competing models on the memory representation of truth-value information: the Spinozan model and the Cartesian model. Both models assume that truth-value information is represented with memory "tags," but the models differ in their coding scheme. According to the Cartesian model, true information is stored with a "true" tag, and false information is stored with a "false" tag. In contrast, the Spinozan model proposes that only false information receives "false" tags. All other (i.e., untagged) information is considered as true by default. Hence, in case of cognitive load during feedback encoding, the latter model predicts a load effect on memory for "false" feedback, but not on memory for "true" feedback. To test this prediction, participants studied trivia statements (Experiment 1) or nonsense statements that allegedly represented foreign-language translations (Experiment 2). After each statement, participants received feedback on the (alleged) truth value of the statement. Importantly, half of the participants experienced cognitive load during feedback processing. For the trivia statements of Experiment 1, we observed a load effect on memory for both "false" and "true" feedback. In contrast, for the nonsense statements of Experiment 2, we found a load effect on memory for "true" feedback only. Both findings clearly contradict the Spinozan model. However, our results are also only partially in line with the predictions of the Cartesian model. For this reason, we suggest a more flexible model that allows for an optional and context-dependent encoding of "true" tags and "false" tags.

Foreign language reduces the longevity of the repetition-based truth effect.

Recent evidence suggests that judgment biases may diminish when a problem is presented in a foreign language. This foreign-language effect has primarily been examined with emotional materials such as risky-choice problems and moral dilemmas. In two experiments, we investigated the effect of foreign-language processing on an emotionally neutral judgment bias: the repetition-based truth effect, the phenomenon that statement repetition enhances the perceived truth of statements. In Experiment 1, we found no evidence for the truth effect to be moderated by the language in which the statements were processed (native language: Hungarian; foreign language: English). In Experiment 2, in turn, we not only manipulated language (native language: German; foreign language: English), but also the retention interval between statement repetitions. Replicating the findings of Experiment 1, language did not moderate the truth effect for statements that were repeated within the same experimental session. However, after a two-week interval, the truth effect was significantly smaller in the foreign-language condition than in the native-language condition. Overall, our findings suggest a faster decay of semantic memory for foreign-language as compared to native-language statements.

Unveiling the truth: warnings reduce the repetition-based truth effect.

Typically, people are more likely to consider a previously seen or heard statement as true compared to a novel statement. This repetition-based "truth effect" is thought to rely on fluency-truth attributions as the underlying cognitive mechanism. In two experiments, we tested the nature of the fluency-attribution mechanism by means of warning instructions, which informed participants about the truth effect and asked them to prevent it. In Experiment 1, we instructed warned participants to consider whether a statement had already been presented in the experiment to avoid the truth effect. However, warnings did not significantly reduce the truth effect. In Experiment 2, we introduced control questions and reminders to ensure that participants understood the warning instruction. This time, warning reduced, but did not eliminate the truth effect. Assuming that the truth effect relies on fluency-truth attributions, this finding suggests that warned participants could control their attributions but did not disregard fluency altogether when making truth judgments. Further, we found no evidence that participants overdiscount the influence of fluency on their truth judgments.

Emotionally enhanced memory for negatively arousing words: storage or retrieval advantage?

People typically remember emotionally negative words better than neutral words. Two experiments are reported that investigate whether emotionally enhanced memory (EEM) for negatively arousing words is based on a storage or retrieval advantage. Participants studied non-word-word pairs that either involved negatively arousing or neutral target words. Memory for these target words was tested by means of a recognition test and a cued-recall test. Data were analysed with a multinomial model that allows the disentanglement of storage and retrieval processes in the present recognition-then-cued-recall paradigm. In both experiments the multinomial analyses revealed no storage differences between negatively arousing and neutral words but a clear retrieval advantage for negatively arousing words in the cued-recall test. These findings suggest that EEM for negatively arousing words is driven by associative processes.

A word of warning: Instructions and feedback cannot prevent the revelation effect.

In recognition tests, participants claim that stimuli appear more familiar after an intervening task (e.g., solving an anagram) than without an intervening task-the revelation effect. In Experiment 1, we warned half of the participants about the revelation effect and asked them to prevent any judgment bias. However, compared to a control group without warning instructions, the revelation effect remained unaltered. In Experiment 2, participants who received warning instructions additionally received accuracy feedback for their recognition judgments. We assumed that feedback would aid participants in detecting any judgment bias. Again, warning instructions and feedback failed to reduce the revelation effect. In Experiment 3, participants demonstrated that they understood the warning instructions and generally believed that they were successful in suppressing the revelation effect. Yet, again, a revelation effect occurred. The experiments suggest that the revelation effect is a robust judgment bias that lies outside of the participants' control.

Initial judgment task and delay of the final validity-rating task moderate the truth effect.

Repeatedly seen or heard statements are typically judged to be more valid than statements one has never encountered before. This phenomenon has been referred to as the truth effect. We conducted two experiments to assess the plasticity of the truth effect under different contextual conditions. Surprisingly, we did not find a truth effect in the typical judgment design when using a ten minutes interval between statement repetitions. However, we replicated the truth effect when changing the judgment task at initial statement exposure or when using an interval of one week rather than ten minutes. Because none of the current truth effect theories can fully account for these context effects, we conclude that the cognitive processes underlying truth judgments are more complex than has hitherto been assumed. To close the theoretical gap, we propose a revised fluency attribution hypothesis as a possible explanation of our findings.

Spinoza's error: memory for truth and falsity.

Two theoretical frameworks have been proposed to account for the representation of truth and falsity in human memory: the Cartesian model and the Spinozan model. Both models presume that during information processing a mental representation of the information is stored along with a tag indicating its truth value. However, the two models disagree on the nature of these tags. According to the Cartesian model, true information receives a "true" tag and false information receives a "false" tag. In contrast, the Spinozan model claims that only false information receives a "false" tag, whereas untagged information is automatically accepted as true. To test the Cartesian and Spinozan models, we conducted two source memory experiments in which participants studied true and false trivia statements from three different sources differing in credibility (i.e., presenting 100% true, 50% true and 50% false, or 100% false statements). In Experiment 1, half of the participants were informed about the source credibility prior to the study phase. As compared to a control group, this precue group showed improved source memory for both true and false statements, but not for statements with an uncertain validity status. Moreover, memory did not differ for truth and falsity in the precue group. As Experiment 2 revealed, this finding is replicated even when using a 1-week rather than a 20-min retention interval between study and test phases. The results of both experiments clearly contradict the Spinozan model but can be explained in terms of the Cartesian model.