Moral perceptions of harm and fairness are instrumental in guiding how an individual navigates moral challenges. Classic research documents that the gender of a target can affect how people deploy these perceptions of harm and fairness. Across multiple studies, we explore the effect of an individual’s moral orientations (their considerations of harm and justice) and a target’s gender on altruistic behavior. Results reveal that a target’s gender can bias one’s readiness to engage in harmful actions and that a decider’s considerations of harm—but not fairness concerns—modulate costly altruism. Together, these data illustrate that moral choices are conditional on the social nature of the moral dyad: Even under the same moral constraints, a target’s gender and a decider’s gender can shift an individual’s choice to be more or less altruistic, suggesting that gender bias and harm considerations play a significant role in moral cognition.

Method Participants in Study 1A were presented with the classic variant of the Trolley Dilemma, the Footbridge Dilemma (Foot, 1978), and queried whether they would push a male or female bystander onto the tracks. Participants in Study 1B were randomly selected to read one of the three versions of the dilemma, where each vignette described a man, woman, or gender-neutral bystander on the bridge. The participant was then asked how willing they were to “push the [man/woman/person] onto the path of the oncoming trolley,” indicating on a 10-point analogue scale willingness to push (WTP). The aim was to determine whether there are observable gender biases during philosophical moral dilemmas, with the key variable being how readily a male or female bystander is pushed onto the tracks (i.e., harmed).

Study 2 Participants In Study 2, 57 adults were recruited from the UK Medical Research Council Cognition and Brain Sciences Unit volunteer panel (32 females; mean age 25.21, SD ± 4.83); sample size was based on previous similar work (FeldmanHall et al., 2012). In order to avoid priming moral attitudes and to minimize explicit moral reasoning during task performance, we recruited participants under the pretense of participating in an economic decision-making study. All participants provided written informed consent, and the study was approved by Cambridge University’s Psychology Research Ethics Committee. An independent group (n = 50; 24 males; mean age 36.1 years, SD ± 14.06) rated the attractiveness, approachability, and feelings toward both targets, finding that the male was significantly more attractive, approachable, and positive than the female target (all ps < .001, see Supplemental Material for details).

Method In the PvG task, participants (deciders) were presented with a series of 20 trials, each requiring a moral decision: benefit oneself financially or prevent harm to another. At the start of the experiment, deciders were given £20 and told that any money left at the end of the task would be multiplied up to 10-fold, giving them as much as £200. On each trial, £1 was at stake, and the choice was how much, if any, of the £1 to give up in order to prevent a painful but harmless electric shock from reaching the target on that trial. The more money paid out on a given trial, the lower the shock level inflicted on the target (index of costly altruism): Paying the full £1 would remove the shock altogether, while paying nothing would mean the target experienced the highest shock level on that trial. The key behavioral variable was how much money (£0–£20) deciders retained across the 20 trials, with larger amounts indicating that personal gain was prioritized over the target’s pain. Effectively, the more money the decider paid, the lower the shock level the target received on a given trial. Consequently, to stop all of the shocks across all 20 trials, deciders would need to spend all £20 (see Supplemental Material for full task details). Deciders were also required to view the administration of the shocks. This allowed us to manipulate the target’s gender by broadcasting a video of either a male target (Condition 1) or female target (Condition 2) responding to the shock (Figure 2A; we used this between-group design to control for the possibility of demand characteristics). Since the shocks were real, videos were prerated by an independent group to be matched across condition, such that both male and female targets elicited similar body and facial pain expressions that were directly yoked to the analogue scale presented to participants. To ensure that other potential factors besides a target’s gender were not driving behavior, we checked (using 8-point Likert-type scales in a subset of our participants during postexperimental questionnaires) that targets were matched on multiple dimensions including their familiarity, all independent t-tests: t(44) = −1.2, p = .234; similarity, t(44) = 0.403, p = .689; likeability, t(44) = −0.563, p = .577; and political orientations, t(44) = −0.007, p = .995. Download Open in new tab Download in PowerPoint Moral Foundations Sacredness Scale (MFSS) To explore potential moderating effects of harm and fairness considerations, we administered the MFSS (Graham & Haidt, 2011) after the PvG, which provides an index of the willingness to earn money at the expense of multiple moral considerations. The MFSS proposes that there are certain psychological foundations on which individuals build their moral systems and are organized along five dimensions (Graham & Haidt, 2011). Since the harm and fairness scales are believed to be most relevant to everyday life (Haidt & Graham, 2007a), and because there is a long-standing debate over which of these two dimensions best predicts moral behavior (Gilligan, 1982; Kohlberg & Hersh, 1977), we used these constructs as predictors of costly altruism. The scale measures how much money an individual is willing to receive to violate moral norms within each of the foundations (see Supplemental Material for more details), encapsulating whether or not a person is motivated (at the expense of money) to care for someone (harm) or is willing to immorally profit off others (fairness).

Results During the PvG task, deciders interacting with a female target kept significantly less money and thus gave significantly lower shocks (n = 34; £8.76/£20, SD ± 5.0) than deciders interacting with a male target, n = 23; £12.54/£20, SD ± 3.9; independent samples t-test: t(55) = −3.16, p = .003, Cohen’s d = .82; Figure 2B. This replicates the findings from Studies 1A and 1B in the real domain and under a different class of moral challenge, illustrating that harm endorsement is attenuated for female targets. Together, this suggests that a target’s gender can powerfully shift the perception of harm and lead to an increase in costly altruism (see Supplemental Material for further analysis including the influence of the decider’s gender on money kept as well as results of Study 4 replicating these findings in an online version of the PvG task). Exploring deciders’ trait sensitivity to harm and fairness considerations (Graham & Haidt, 2011) revealed that female deciders reported significantly greater sensitivity to harm than male deciders, female mean harm sensitivity = 30.4, SD ± 5.1, male mean harm sensitivity = 26.2, SD ± 5.8; independent t-test: t(55) = −2.88, p = 0.02, Cohen’s d = .77. We did not observe a difference in deciders’ trait fairness levels, female mean fairness sensitivity = 25.0, SD ± 9.7, male mean fairness sensitivity = 27.1, SD ± 7.9; independent t-test: t(55) = 0.89, p = 0.38. To examine whether these individual trait differences in moral orientations moderate the relationship between altruism and a target’s and decider’s gender, we performed multiple regression analyses (Table 1). Money kept/shock delivered (index of costly altruism) was the dependent variable. The predictors at the first step (Model 1) were target’s gender, decider’s gender, and deciders’ individual trait harm scores (all z-scored). At the second step (Model 2), we entered each of the product terms of these variables, and at the third step (Model 3), we entered the three-way interaction term. Significant moderation is indicated by the fit of the model improving with each subsequent step (Aiken & West, 1991). We also ran this same regression with deciders’ fairness scores. Table 1. Multiple Hierarchal Regression Study 2. View larger version We found a significant moderating role of harm sensitivity on both the effects of a target’s gender and a decider’s gender on altruistic behavior, Model 2: ΔF(3, 50) = 4.59, p = .006, Δr2 = .15, r2 = total .46; Table 1. Figure 2C and 2D plots these significant interactions using the method of simple slopes (Aiken & West, 1991). We found that higher levels of trait harm sensitivity predicted greater altruism for female targets but not male targets (Figure 2C). That is, deciders high in harm sensitivity interacting with a female target kept significantly less money, thus preserving the female target’s physical welfare. We also found that trait levels of harm sensitivity played a moderating role on a decider’s gender and their subsequent choice to preserve the welfare of the target: Male deciders with low levels of trait harm sensitivity were significantly more selfish than males deciders with high levels of trait harm sensitivity (Figure 2D). This finding did not hold for female deciders, as females exhibited the same altruistic behavior regardless of their levels of trait harm sensitivity. Furthermore, there was no clear interaction relationship between an decider’s gender, a target’s gender, and trait harm sensitivity, Model 3: ΔF(1, 49) = 0.08, p = .78, Δr2 = .001, r2 = total .46; Table 1. While we found that fairness considerations influenced altruistic choice overall, Model 1: ΔF(3, 52) = 7.71, p < .001, Δr2 = .31, r2 = total .27, we observed no evidence that fairness considerations had a moderating role on gender and altruistic choice, Model 2: ΔF(3, 49) = 2.1, p = .11, Δr2 = .08, r2 = total .31. Together, these results demonstrate a strong relationship between a decider’s sensitivity to harm considerations and the target’s gender on altruistic choice as well as a strong relationship between a decider’s gender and their sensitivity to harm on altruistic choice.

Studies 3A, 3B, and 3C Given that we observed a target’s gender can bias one’s readiness to engage in harmful actions and that a decider’s considerations of harm—but not fairness concerns—modulate costly altruism, we next sought to explore possible motivations supporting this gender and harm interaction. One explanation is that females typically evoke more positive attitudes than males (Fazio & Olson, 2003) and are thus more likely to reap greater prosocial treatment. However, our post-task questionnaires probing attitudes toward the target significantly favored the male target, indicating that positive feelings for females are unlikely to be underlying the observed effect. An alternative explanation is rooted in the interaction between harm endorsement and adherence to societal norms, with the idea that it is more socially unacceptable to harm a female than a male (Becker & Wright, 2011; Crew, 1991; Viki, Abrams, & Hutchison, 2003; Wood & Eagly, 2002, 2009). There is also the possibility that individuals find it more emotionally aversive to harm a female, which in turn could enhance altruistic behavior in the PvG task (Cushman et al., 2012; Miller, Hannikainen, & Cushman, 2014; Pizarro, 2000). In the next studies, we probe whether these motivations might underlie an individual’s reluctance to harm a female target for monetary gain. Participants and Methods A total of 352 participants were recruited for Studies 3A–3C, see Supplemental Material for details. Study 3A was a hypothetical analogue of the PvG task—where target’s gender was randomly manipulated to be female, male, or gender neutral (a between-subject design). Participants were queried about how much money most volunteers would keep and probed about societal perceptions of (1) harm, (2) pain tolerance, and (3) the chivalrous notion that men should protect women. Study 3B presented a subset of the same questions in Study 3A, except that questions pertained to both males and females (a within-subjects design). Study 3C randomly presented one of the three versions of the hypothetical PvG, and probed emotional aversion to the dilemma. See Supplemental Material for full list of questions and descriptive statistics from analyses in Studies 3A–3C; answers were recorded on 10-point Likert-type scales.

Results When probed about what other volunteers would do in the hypothetical analogue of the PvG, participants in Study 3A reported most volunteers would keep significantly less money when engaging with a female than a male or gender-neutral target, ANOVA: F(2, 148) = 3.8, p = .024, η2 = .05. Societal perceptions of pain tolerance revealed that women are believed to have a significantly lower pain tolerance than either men or a person whose gender was unspecified, ANOVA: F(2, 148) = 10.2, p < .001, η2 = .12. A similar pattern was observed regarding commonly held social norms that dictate how fair it is to harm a (man/woman/person); harming females was perceived as significantly more unfair than harming either a man or a gender-neutral person, ANOVA: F(2, 148) = 7.28, p = .001, η2 = .09. When queried about who should be saved first on a sinking ship, only one participant reported that men should be saved first (Pearson’s χ2 = 78.3, 2 df, p < .001, η2 = .52), and the rest of participants responded that there should either be no order or that women should be saved first (Figure 3A). Finally, participants reported that society generally subscribes to the chivalrous notion that men should lend more protection from harm to women than men, t(150) = −4.3, p < .001, Cohen’s d = .70. Download Open in new tab Download in PowerPoint Study 3B confirmed these findings in a within-subject design. Specifically, we observed that according to social norms, it is significantly (1) more morally unacceptable to harm a female for money, paired samples t-test: t(49) = −2.6, p = .01, Cohen’s d = .37: Figure 3B; (2) more unfair to harm a female, paired samples t-test: t(49) = −5.03, p < .001, Cohen’s d = .34: Figure 3C; and men have a significantly greater tolerance to pain, paired samples t-test: t(49) = 4.1, p < .001, Cohen’s d = .98: Figure 3D. In Study 3C, we tested whether harm inflicted on males and females elicits different levels of emotional aversion. Participants responded to three questions relating to their own emotional aversion and level of emotional intensity after reading the hypothetical PvG scenario. Across conditions (male/female/gender neutral), we found no differences in the level of emotional aversion or level of emotional intensity (all ps > .1). That is, participants reported similar high levels of emotional aversion to reading about a male, female, and gender-neutral target in the PvG dilemma (see Supplemental Material for details). Across these three studies, we investigate possible motivations supporting the finding that a target’s gender can bias an individual’s willingness to engage in harmful actions. The findings suggest that social norms regarding gender and harm considerations likely account for greater harming behavior toward a male than a female target. Moreover, there are widely held societal perceptions that females are less tolerant to pain, that it is unacceptable to harm females for personal gain, and that society endorses chivalrous behavior. Surprisingly, we found no differences in emotional aversion to reading about harming males versus females. These findings confirm perceptions of gender bias, and that these biases interact with harm considerations, helping to disambiguate why males are harmed more during the PvG task. While it is equally emotionally aversive to hurt any individual—regardless of their gender—that society perceives harming women as more morally unacceptable, suggests that gender bias and harm considerations play a large role in shaping moral action.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was funded by the UK Medical Research Council and Columbia University. Supplemental Material

The online data supplements are available at http://spps.sagepub.com/supplemental.