Utilitarian Moral Judgment Exclusively Coheres with Inference from Is to Ought

Abstract

Faced with moral choice, people either judge according to pre-existing obligations (deontological judgment), or by taking into account the consequences of their actions (utilitarian judgment). We propose that the latter coheres with a more general cognitive mechanism - deontic introduction, the tendency to infer normative ('deontic') conclusions from descriptive premises (is-ought inference). Participants were presented with vignettes that allowed either deontological or utilitarian choice, and asked to draw a range of deontic conclusions, as well as judge the overall moral rightness of each choice separately. We predicted and found a selective defeasibility pattern, in which manipulations that suppressed deontic introduction also suppressed utilitarian moral judgment, but had little effect on deontological moral judgment. Thus, deontic introduction coheres with utilitarian moral judgment almost exclusively. We suggest a family of norm-generating informal inferences, in which normative conclusions are drawn from descriptive (although value-laden) premises. This family includes deontic introduction and utilitarian moral judgment as well as other informal inferences. We conclude with a call for greater integration of research in moral judgment and research into deontic reasoning and informal inference.

Keywords: causal inference; defeasibility; deontic introduction; deontic reasoning; deontological moral judgment; is-ought inference; new paradigm; utilitarian moral judgment.

FIGURE 1

Processing model for deontic introduction. Illustrations from the trolley problem in italics. Adapted from: Elqayam et al. (2015). Copyright 2015 American Psychological Association.

FIGURE 2

Experiment 1: Mean moral rightness ratings, from 1 (entirely morally wrong) to 7 (entirely morally right), as a function of type of judgment and goal conflict condition. Error bars represent 1 SE. The difference between the goal suppression condition and the no-suppression condition is significant for utilitarian (solid blue line) but not for deontological (dashed red line) judgment.

FIGURE 3

Experiment 1: Mean moral rightness ratings, from 1 (entirely morally wrong) to 7 (entirely morally right), as a function of type of judgment and normative conflict condition. Error bars represent 1 SE. The difference between the low normative conflict condition and the high normative conflict condition is significant for utilitarian (solid blue line) but not for deontological (dashed red line) judgment.

FIGURE 4

Experiment 1: Mean conclusion ratings, from 1 (Definitely does not follow) to 7 (Definitely follows), as a function of deontic operator, type of inference and normative conflict condition. Error bars represent 1 SE. The difference between the low normative conflict and the high normative conflict condition is significant for all ratings of utilitarian inference strength except ‘may,’ and for none of the ratings of deontological inference strength.

FIGURE 5

Experiment 1: Mean conclusion ratings, from 1 (Definitely does not follow) to 7 (Definitely follows), as a function of deontic operator, type of inference and goal conflict condition. Error bars represent 1 SE. The difference between the goal suppression and the no goal suppression condition is significant for all ratings of utilitarian inference strength except ‘may,’ and for none of the ratings of deontological inference strength.

FIGURE 6

Experiment 2: Mean moral rightness ratings, from 1 (entirely morally wrong) to 7 (entirely morally right), as a function of type of judgment and causal suppression condition. Error bars represent 1 SE.

FIGURE 7

Experiment 2: Mean moral rightness ratings, from 1 (entirely morally wrong) to 7 (entirely morally right), as a function of type of judgment and normative conflict condition. Error bars represent 1 SE.

FIGURE 8

Experiment 2: Mean conclusion ratings, from 1 (Definitely does not follow) to 7 (Definitely follows), as a function of deontic operator, type of inference and causal suppression condition. Error bars represent 1 SE.

FIGURE 9

Experiment 2: Mean conclusion ratings, from 1 (Definitely does not follow) to 7 (Definitely follows), as a function of deontic operator, type of inference and normative conflict condition. Error bars represent 1 SE.