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

Have you ever heard of the veracity bias? It is a phenomenon with two possible meanings: on the one hand, it is the tendency to believe that others are honest and therefore tell the truth, and on the other, it is the tendency to remember "false" information such as true.

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

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Truthfulness bias: two meanings

First of all, we must take into account that the veracity bias has two possible meanings.

1. Meaning 1: Believing that others are honest

The first meaning of truthfulness bias, a term introduced by Zuckerman et al. in 1981, is the one who defines it as the tendency we have to believe or assume that other people are honest (and that they tell the truth, that they are sincere).

That is, according to the veracity bias, we would assume that others are much more honest than they really are.

2. Meaning 2: Remember “false” information as true

The second meaning of the veracity bias, which has been recently investigated 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 explained to us to be false.

That is, according to this bias, we tend to remember information labeled as “false” as true. Sounds a bit contradictory, doesn't it?

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Scientific investigation of both phenomena

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

1. Truthfulness bias 1: believing that others are honest

What does the research suggest when it analyzes the veracity bias, understood as the “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 veracity bias, and we tend to consider that others generally tell us the truth; this would explain why our precision when judging truths is good, and when judging lies, is a little poorer (Levine et al., 1999; Masip et al., 2002b).

In subsequent studies, specifically in a meta-analysis conducted by Bond and DePaulo, it was found that the % average of the truth judgments was 55% (by chance, it is expected that this % is 50%, that is, that the average went up). This % made the accuracy of the judges when judging statements as true, reached up to 60%. This last percentage was slightly higher than when judges had to judge false statements (which stood at 48.7%).

policemen

We have talked about judges, but what about the police? 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 inverted, and it is observed how in the majority of times the precision for detecting false statements is higher than the precision for detecting false statements true.

Mental bias

A possible explanation for this is that policemen have a greater tendency to make false judgments and not so much truth; in other words, they show mendacity bias. How is this bias defined? It consists of the tendency to make more false judgments than truth (which is fulfilled in the police).

In non-professionals (that is, neither judges nor police nor belonging to the legal sector), on the other hand, this bias does not appear, since according to the research (Levine, Park, & McCornack, 1999), we would tend to be more accurate in judging the truth than the lie (i.e., the mendacity bias is reverses).

2. Truth bias 2: remembering “false” information as true

Studies prior to that of Pantazi et al. (2020), already mentioned, reveal that people, by themselves, are biased by the truth; this means that we tend to believe 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 consists of a kind of inefficiency that people present when calibrating the quality of the information provided by the medium, which also affects when it comes to “correcting” said information information.

Development study Pantazi et al. (2020)

To demonstrate the veracity bias, the experimenters in the study we discussed proceeded as follows: they designed an experimental paradigm where Moot jurors (condition or study 1) and professional jurors (condition or study 2) were asked to read two crime reports.

Said reports contained aggravating or mitigating information of such crimes, and it was explicitly specified that this information was false.

What they evaluated in the study was: the decisions made by the juries in relation to the cases presented (that is, the sentences), including how false information influenced them, as well as their memory (and, of course, also how the false information affected it).

In short, we wanted to check whether the veracity bias appeared in these groups, in the legal context in which the aforementioned study is framed.

Findings

What do the findings of this experiment suggest regarding veracity bias?

Basically, what both mock jurors and professional jurors exhibited veracity bias; This means that all the participants had made decisions, in relation to the cases, biased by false information, and that their memory was also biased by said information (information false).

Specifically, the results of condition or study 2 (professional jury) indicated that professional judges had been affected (or influenced) by false information when issuing their verdicts, in a similar way to what happened with study 1 (jury simulated). That is, to a similar degree.

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

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

Memory

What did you observe in the judges regarding the evaluated memory? The results show how jurors, both mock and professional, showed a tendency to recall, in an erroneous way, aggravating information and explicit as false.

A curious fact revealed by the study is that the ability of judges to filter or discriminate false information from the one that is not (whether we analyze his decisions and sentences, or his memory), did not depend on his years of experience.

Bibliographic references:

Garrido, E., Masip, J. and Alonso, H. (2009). The ability of police officers to detect lies. Journal of criminal law and criminology, 3 (2), pp. 159-196. Levine, T. R., Park, H. S., & McCornack, S. TO. (1999). Accuracy in detecting truths and lies: Documenting the “veracity effect.” Communication Monographs, 66, 125-144. Masip, J., Garrido, E. & Herrero, C. (2002). Legal Psychology Yearbook. McCornack, S.A. & Parks, M.R. (1986) Deception Detection and Relationship Development: The Other Side of Trust. Pantazi, M., Klein, O. & Kissine, M. (2020). Is justice blind or myopic? An examination of the effects of meta-cognitive myopia and truth bias on mock jurors and judges. Judgment and Decision Making, 15(2): 214–229.