Does telling white lies signal pro-social preferences?

The opportunity to tell a white lie (i.e., a lie that benefits another person) generates a moral conflict between two opposite moral dictates, one pushing towards telling always the truth and the other pushing towards helping others. Here we study how people resolve this moral conflict. What does telling a white lie signal about a person’s pro-social tendencies? To answer this question, we conducted a two-stage 2x2 experiment. In the first stage, we used a Deception Game to measure aversion to telling a Pareto white lie (i.e., a lie that helps both the liar and the listener), and aversion to telling an altruistic white lie (i.e., a lie that helps the listener at the expense of the liar). In the second stage we measured altruistic tendencies using a Dictator Game and cooperative tendencies using a Prisoner’s dilemma. We found three major results: (i) both altruism and cooperation are positively correlated with aversion to telling a Pareto white lie; (ii) both altruism and cooperation are negatively correlated with aversion to telling an altruistic white lie; (iii) men are more likely than women to tell an altruistic white lie, but not to tell a Pareto white lie. Our results shed light on the moral conflit between pro-sociality and truth-telling. In particular, the first finding suggests that a significant proportion of people have non-distributional notions of what the right thing to do is: irrespective of their economic consequences, they tell the truth, they cooperate, they share their money.

💡 Research Summary

The paper investigates whether telling “white lies” – lies that benefit another person – signals a person’s prosocial preferences. To do this, the authors designed a two‑stage laboratory experiment with a 2 × 2 factorial structure. In the first stage participants played a variant of the Deception Game introduced by Gneezy et al. (2013). Two treatments were used. In the Pareto white‑lie (PWL) treatment, the liar (Player 1) could either tell the truth (both players receive $0.10) or lie (both players receive $0.15). In the altruistic white‑lie (AWL) treatment, truth again yields $0.10 for each, but a lie gives the liar $0.09 and the passive partner $0.30. Thus, PWL creates a situation where the lie is jointly beneficial, whereas AWL creates a situation where the lie benefits only the partner at a small cost to the liar.

In the second stage participants were randomly assigned to either a one‑shot anonymous Dictator Game (DG) or a one‑shot anonymous Prisoner’s Dilemma (PD). In the DG each subject received $0.20 and decided how much to transfer to an anonymous recipient. In the PD each subject received $0.10 and chose either to transfer it (cooperate, giving the partner $0.20) or keep it (defect). These two games capture distinct dimensions of prosociality: unilateral altruism (DG) and mutual cooperation (PD).

A total of 1,212 U.S. participants recruited via Amazon Mechanical Turk passed comprehension checks (59 % male, mean age ≈ 34). In the first stage, 83 % of participants chose to lie in the PWL condition, whereas only 23 % lied in the AWL condition, replicating earlier findings that people are far more willing to lie when they also profit. In the second stage, average DG donations were 22 % of the endowment, and cooperation in the PD was observed in 35 % of the decisions.

Statistical analysis employed linear regression for DG donations and logistic regression for PD cooperation, with the main independent variables being the binary choice to lie (or not) in each white‑lie treatment, plus demographic controls (sex, age, education). The key results are: (i) participants who refused to tell a PWL (i.e., who preferred truth) gave lower DG donations and were less likely to cooperate in the PD. This positive correlation between PWL aversion and lower prosocial behavior suggests that those who uphold truthfulness as a non‑economic moral principle also act less altruistically and cooperatively. (ii) Conversely, participants who refused to tell an AWL (i.e., who avoided a lie that harms themselves) gave higher DG donations and were more likely to cooperate in the PD. The negative correlation indicates that aversion to self‑costly altruistic lies is associated with stronger prosocial preferences. (iii) Gender analysis revealed that men were significantly more likely than women to tell an AWL, but there was no gender difference in PWL behavior. Age showed a modest positive effect on DG giving; education had no significant impact.

These findings extend the literature on lying aversion and prosociality. While Cappelen et al. (2013) previously documented a negative relationship between PWL aversion and DG giving, the present study broadens the scope by simultaneously examining two types of white lies and two distinct prosocial games, thereby capturing the multidimensional nature of prosociality. The pattern of results supports the existence of a “non‑distributional” moral norm: a commitment to truth that operates independently of material outcomes. Individuals who prioritize this norm tend to be less generous and less cooperative, whereas those who are reluctant to incur personal costs for the sake of a lie that benefits only others tend to be more generous and cooperative.

Limitations include the reliance on an online U.S. sample, which may limit cross‑cultural generalizability, and the fact that the experimental setting abstracts away from many real‑world contextual cues that influence lying and cooperation. Moreover, the one‑shot nature of the games does not capture dynamic or repeated‑interaction effects. Future research could explore cultural variation, longitudinal designs, and neurobiological manipulations (e.g., oxytocin administration) to further elucidate the causal mechanisms linking moral dilemmas about truth‑telling and prosocial behavior.