Subtle priming of subtraction versus addition: a spill-over effect of math / La inducción sutil de sumar vs. restar: un efecto indirecto de las matemáticas

Studies on bias correction have often used blatant inductions to motivate people to reduce the mental impact of perceived biases. In the current research, we test a relatively unexplored, subtle way of inducing bias correction based on the activation of different calculative mindsets. Across two studies, participants were exposed to an advertisement introducing a new consumer product delivered by a credible or non-credible source. Then, as part of an ostensibly unrelated study, participants completed mathematical operations that involved subtracting or adding. Study 1 revealed that when participants were primed with an addition calculative mindset, an expert source elicited more favourable attitudes towards the product than a non-expert source. This pattern illustrates the traditional effect of source credibility on persuasion. In contrast, within the subtraction calculative mindset condition, persuasion was no different between an expert and a non-expert source. These results were obtained exclusively under high thinking conditions (e.g., for participants high in Need for Cognition). This finding can be interpreted as if the effect of source credibility was subtracted from the evaluative judgement. Study 2 replicated this two-way interaction using different materials and inductions. The present research has implications for bias correction, procedural priming, persuasion and beyond.