The side-effect effect (SEE) is the observation that people's intuition about whether an action was intentional depends on whether the outcome is good or bad. The asymmetric response, however, does not represent all subjects' judgments (Nichols and Ulatowski, 2007). It remains unexplored on subjective factors that can mediate the size of SEE. Thus, the current study investigated whether an individual related factor, specifically, whether adults' intensity of caring about an outcome of someone's actions influences their judgments about whether that person intended the outcome. We hypothesized that participants' judgments about fictional agents' responsibility for their action's side-effects would depend on how much they care about the domain of the side-effect. In two experiments, the intensity of caring affected participants' ascription of intention to an agent's negative unintended side-effect. The stronger ascription of intentionality to negative than positive side-effects (i.e., the SEE; Knobe, 2003) was found only in domains in which participants reported higher levels of caring. Also, the intensity of caring increased intentionality attributions reliably for negative side-effects but not for positive side-effects. These results suggest that caring about a domain mediates an asymmetrical ascription of intentionality to negative more than positive side-effects.
