Prior studies only measured sacrificial dilemmas, which overstate the downsides.
Kahane et al. ’18 [Guy et al.; 2018; Fellow and in Philosophy at Pembroke College, Oxford, and Professor at the Faculty of Philosophy, University of Oxford; Psychological Review, “Beyond Sacrificial Harm: A Two-Dimensional Model of Utilitarian Psychology,” vol. 125 no. 2]
What is the relationship between empathic concern and utilitarian tendencies? Some work has suggested that deontological—but not utilitarian—tendencies are related to increased empathic concern (Choe & Min, 2011; Conway & Gawronski, 2013; Gleichgerrcht & Young, 2013; Patil & Silani, 2014). Yet on theoretical grounds, such findings are puzzling, given that empathy has been claimed to be a central psychological source of utilitarianism (Hare, 1981; Smart & Williams, 1973). However, once we take into account that these prior studies all used sacrificial dilemmas as a measure of utilitarianism, the discrepancy can be explained. Such dilemmas focus exclusively on the negative dimension of utilitarianism, and specifically on willingness to cause harm for the greater good. If one considers killing one person to save five others, a stronger empathetic response is likely to be an obstacle to endorsing such instrumental harm. By contrast, the historical tie between utilitarianism and empathy is most plausibly related to utilitarianism’s positive aspect, that is, its impartial concern for everyone’s welfare. It is therefore likely that the previously found negative relationship between empathic concern and utilitarianism may have been driven entirely by instrumental harm, rather than impartial beneficence.