Covariation bias for blood-injury stimuli and aversive outcomes

Three illusory correlation experiments were conducted to determine whether a fear-relevant covariation bias could be demonstrated using different types of fear-relevant stimuli from the blood-injury phobia category. In each experiment, women high and low on blood-injury fear were presented with fear-relevant slides depicting blood or injury, as well as slides from two neutral categories. A shock (aversive outcome), or a tone or no outcome (neutral outcomes) followed each of the 72 slides. Although the relationship between slide types and outcomes was random, subjects in all three experiments overestimated the co-occurrence of shock and blood-injury slides relative to all other slide-outcome combinations. However, there was no significant effect of blood-injury fear on this bias, indicating that, regardless of their blood-injury fear level, humans show an associative bias to selectively associate blood-injury stimuli with aversive outcomes.