Are the symptoms really remitting? How the subjective interpretation of outcomes can produce an illusion of causality

Abstract

Judgments of a treatment’s effectiveness are usually biased by the probability with which the outcome (e.g., symptom relief) appears: even when the treatment is completely ineffective (i.e., there is a null contingency between cause and outcome), judgments tend to be higher when outcomes appear with high probability. In this research, we present ambiguous stimuli, expecting to find individual differences in the tendency to interpret them as outcomes. In Experiment 1, judgments of effectiveness of a completely ineffective treatment increased with the spontaneous tendency of participants to interpret ambiguous stimuli as outcome occurrences (i.e., healings). In Experiment 2, this interpretation bias was affected by the overall treatment-outcome contingency, suggesting that the tendency to interpret ambiguous stimuli as outcomes is learned and context-dependent. In conclusion, we show that, to understand how judgments of effectiveness are affected by outcome probability, we need to also take into account the variable tendency of people to interpret ambiguous information as outcome occurrences.

Interpretation of ambiguous trials along with reasoning strategy is related to causal judgements in zero-contingency learning

“…However, this effect was not present in Study 2, nor in the Blanco et al (2020) study using a null contingency task. It should be noted that Blanco et al (2020) replicated their study using a positive contingency learning task (∆ p = 0 86 . ).…”

“…We specifically hypothesised that Statistical reasoners would show a greater tendency to interpret ambiguous cues as indicating a state of wellness than Counterexample reasoners. We also expected to replicate the previous results of Blanco et al (2020), that is, that there would be a positive relation between the tendency to interpret ambiguous cues as indicating a state of wellness and final causal attributions.…”

“…This tendency appeared after being exposed to trials suggesting the existence of a positive contingency, which suggests some kind of confirmation bias where participants end up categorising ambiguous trials consistently with the overall contingency. While speculative, it is useful to note that Study 1 presented a minimal number of cues to patient state, while both Study 2 and the Blanco et al (2020) study used more complex cues. It is possible that when the contingency is not extreme (i.e., neither high nor low) the cognitive load required to process more complex representations of patient state might interfere with the concurrent processing of presence/absence of the treatment.…”

“…For each trial, the state of the patient was represented by different combinations of cues, going from all of one kind to completely ambiguous (equal number of good and bad images). As in Blanco et al (2020), participants were asked to categorise each set of cues as indicating that the patient was well or not, but were given no instructions about how to interpret patient states. Participants were also given the Strategy Assessment Task used to determine reasoning strategy.…”

“…As Blanco et al (2020) remarked, there are clear individual differences in the extent to which people generate such interpretations. Thus, to better understand how humans process contingency information, it seems important to understand what factors characterise this variability.…”