Truthfulness bias: what it is and how it affects our perception

Have you ever heard of low veracity? It is a two-way possible phenomenon: on the one hand, it is the tendency to believe that others are honest and therefore tell the truth, and on the other hand, it is the tendency to remember information. “Fake” like a real one.

In this article, we bring you the results of scientific research for each of these two meanings, because the phenomenon of low veracity has been studied in two ways. As we will see, this is a concept closely related to criminal investigation and legal psychology. But why? Let’s find out.

    Truthfulness bias: two meanings

    First of all, we must keep in mind that the veracity bias has two possible meanings.

    1. Meaning 1: Believe that others are honest

    The first meaning of low veracity, a term introduced by Zuckerman et al. in 1981, it was he who defined him as the tendency we have to believe or assume that others are honest (And they are telling the truth, they are sincere).

    In other words, based on the truthfulness bias, we would assume that others are much more honest than they actually are.

    2. Meaning 2: Remember that “false” information is true

    The second meaning of low veracity, which was recently explored in a study by Pantazi, Klein & Kissine (2020), refers to the fact that people we tend to mistakenly remember as true information that has been explicitly told to be false.

    In other words, according to this bias, we tend to remember ourselves as real information labeled as “fake”. Sounds a bit contradictory, doesn’t it?

      Scientific research of the two phenomena

      But what exactly does scientific research say about truth bias? We will analyze the research that has been carried out in relation to this phenomenon, differentiating the two meanings attributed to it.

      1. Truth Bias 1: Believe that others are honest

      What does research suggest when it analyzes the truth bias, seeing it as an “excessive” belief in the honesty of others? Are we good at detecting lies?

      According to a study by Levine, Park and McCornack (1999), we tend to identify truths more easily than lies.

      But why? According to the authors, precisely because we manifest this bias of truthfulness, and we tend to consider that others are generally telling us the truth; this would explain why our accuracy in judging truths is good, and in judging lies, being a little worse (Levine et al., 1999; Masip et al., 2002b).

      In later studies, especially in a meta-analysis by Bond and DePaulo, the average% true judgments were found to be 55% (by chance this% should be 50%, or if the average increased ). This% allowed the accuracy of the judges to judge the statements as true, reaching 60%. This last percentage it was slightly higher than it looks when judges had to judge false statements (Which stood at 48.7%).


      We talked about the judges, but what about the cops? According to research by Meissner and Kassin (2002), Bond and DePaulo (2006) and Garrido et al. (2009), in the police, this trend that we have explained is reversed, and we observe that in most cases, the precision of the detection of false statements is higher than that of the detection of true statements.

      The bias of lies

      One possible explanation for this is that cops have a greater tendency to lie and less true judgments; in other words, they show the bias of lying. How is this bias defined? It is about the tendency to make more judgments of lies than of truth (which is accomplished among the cops).

      Among lay people (i.e., neither judges, nor police, nor members of the legal sector), however, this bias does not appear, because research (Levine, Park, & McCornack, 1999) shows that we would tend to be more precise in judging the truth rather than the lie (i.e. the bias of the lie is reversed).

      2. Truth Bias 2: Remembering “false” information as true

      Studies prior to that of Pantazi et al. (2020), already mentioned, reveal that people, in themselves, are biased by the truth; this means that we tend to believe the information we receive, even when it is marked or labeled as false information.

      According to the study by Pantazi et al. (2020), the veracity bias is a kind of inefficiency that we presented to people when it comes to calibrating the quality of the information provided by the medium, which also affects when it comes to ” correct ”this information.

      Development of the Pantazi et al. (2020)

      To demonstrate the veracity bias, the experimenters of the study we discussed did the following: design an experimental paradigm where mock juries (condition or study 1) and professional juries (condition or study 2) were asked to read two crime reports.

      These reports contained aggravating or mitigating information on these offenses, and it was explicitly stated that this information was false.

      What they assessed in the study was: decisions made by juries in relation to the cases raised (i.e. judgments), including how false information influenced them, as well as their memory (And, of course, also how the misinformation affected her).

      In short, we wanted to see if the veracity bias appeared in these groups, in the legal context in which the study took place.


      What do the results of this experiment suggest about low veracity?

      Basically, that simulated juries and professional juries presented the bias of veracity; this means that all the participants had made decisions, in relation to the cases, biased by the false information, and that their memory was also distorted by this information (false information).

      Specifically, the results of Condition or Study 2 (Professional Jury) indicated that professional judges were affected (or influenced) by false information when posting their verdicts, as happened with study 1 (mock jury). In other words, to a similar degree.

      On the other hand, it is also true that some variability was detected in the decisions of the judges, once the false information was heard, compared to the years of imprisonment they proposed for the accused. (through the different cases).

      In addition, the results of the study reveal that 83% of the time, judges handed down longer sentences after receiving false information or evidence that aggravated the crime., That when they received false evidence (and not so much information).


      What did they observe in the judges regarding the evaluated report? The results show how the juries, both simulated and professional, they showed a tendency to wrongly recall aggravating and explicit information as being false.

      A curious fact that the study reveals is that the ability of judges to filter or distinguish false information from what is not (whether we analyze their decisions and judgments, like their memory), did not depend on their years. of experience.

      Bibliographical references:

      Garrido, E., Masip, J. and Alonso, H. (2009). The ability of politicians to detect lies. Journal of Criminal Law and Criminology, 3 (2), pages 159-196. Levine, TR, Park, HS, and McCornack, SA (1999). Accuracy in Detecting Truths and Lies: Documenting the “Truthfulness Effect”. Communication Monographs, 66, 125-144. Masip, J., Garrido, E. and Herrero, C. (2002). Yearbook of Legal Psychology. McCornack, SA and Parks, MR (1986) Detecting Deception and Building Relationships: The Other Side of Trust. Pantazi, M., Klein, O. and Kissine, M. (2020). Is justice blind or myopic? A review of the effects of metacognitive myopia and truth bias on jurors and simulated judges. Judgment and Decision Making, 15 (2): 214-229.

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