The means/side-effect distinction in moral cognition: A meta-analysis

Abstract

Experimental research suggests that people draw a moral distinction between bad outcomes brought about as a means versus a side effect (or byproduct). Such findings have informed multiple psychological and philosophical debates about moral cognition, including its computational structure, its sensitivity to the famous Doctrine of Double Effect, its reliability, and its status as a universal and innate mental module akin to universal grammar. But some studies have failed to replicate the means/byproduct effect especially in the absence of other factors, such as personal contact. So we aimed to determine how robust the means/byproduct effect is by conducting a meta-analysis of both published and unpublished studies (k = 101; 24,058 participants). We found that while there is an overall small difference between moral judgments of means and byproducts (standardized mean difference = 0.87, 95% CI 0.67 -1.06; standardized mean change = 0.57, 95% CI 0.44 -0.69; log odds ratio = 1.59, 95% CI 1.15 -2.02), the mean effect size is primarily moderated by whether the outcome is brought about by personal contact, which typically involves the use of personal force.Total Word Count: 9,758

The influence of war on moral judgments about harm

“…This difference in judgment across switch and footbridge scenarios is robust and has been the focus of much attention in moral psychology (Cushman, 2014). Explanations put forward for the difference include factors such as the distinction between personal and impersonal force (Greene, Sommerville, Nystrom, Darley, & Cohen, 2001), the locus of action (Wiegmann & Waldmann, 2014), the contact principle (Cushman et al, 2006), intention (Cushman et al, 2006;Feltz & May, 2017), and, relatedly, the doctrine of double effect (DDE) (to which we will return; Mikhail, 2011;Watkins & Laham, 2016). In studying these and other factors proposed to underlie moral judgments, researchers often develop variations on trolley problems: New pairs of hypothetical dilemma scenarios that capture the factor under investigation.…”

“…People do indeed make moral judgments that are consistent with the DDE. Killing is generally judged as more morally wrong when the harm is intended as a means to a desired end than when the harm occurs as an unintended but foreseen side-effect of achieving the desired end (Feltz & May, 2017). In trolley problem dilemmas, this is thought to provide one explanation for why moral judgments are harsher in the footbridge scenariowhere the one person is being killed as a means to an end, and the DDE is violated-than in the switch scenario-where the one person is being killed as a side effect, and the DDE is upheld (Cushman, 2008(Cushman, , 2014.…”

Moral Judgment as Categorization (MJAC)

“…Hester & Gray, 2020; see also Feltz & May, 2017). We predict that people will be more lenient in their judgments of (b) than of (a) as people appear to be more lenient in their judgments of people they are close to, versus strangers (Forbes, 2018;Hofmann et al, 2014;Lee & Holyoak, 2020;Weidman et al, 2020).…”

The Influence of War on Moral Judgments about Harm

“…Explanations put forward for the difference include factors such as the distinction between personal and impersonal force (Greene, Sommerville, Nystrom, Darley, & Cohen, 2001), the locus of action (Wiegmann & Waldmann, 2014), the contact principle (Cushman et al, 2006), intention (Cushman et al, 2006;Feltz & May, 2017), and, relatedly, the doctrine of double effect (to which we will return; Mikhail, 2011;Watkins & Laham, 2016). In studying these and other factors proposed to underlie moral judgments, researchers often develop variations on trolley problems: New pairs of hypothetical dilemma scenarios that capture the factor under investigation.…”

“…People do indeed make moral judgments that are consistent with the DDE. Killing is generally judged as more morally wrong when the harm is intended as a means to a desired end, than when the harm occurs as an unintended but foreseen side-effect of achieving the desired end (Feltz & May, 2017). In trolley problem dilemmas, this is thought to provide one explanation for why moral judgments are harsher in the footbridge scenario -where the one person is being killed as a means to an end, and the DDE is violated -than in the switch scenario -where the one person is being killed as a side effect, and the DDE is upheld (Cushman, 2008(Cushman, , 2014.…”