Why do we collectively donate billions of dollars to charity, but pay relatively little attention to the impact of our dollars? Abhor the thought of murdering a child, but think little of buying lattes with money that we could use to provide a child with lifesaving medicine? My research integrates evolutionary game theory with laboratory experiments to study the hidden incentives that shape our preferences, beliefs, and ideologies. My recent research has focused in particular on morality and altruism: inefficient giving, the omission-commission distinction, strategic ignorance, and the malleability of empathy.
Burum. B., Hoffman, H. & Nowak, M. An evolutionary explanation for inefficient giving.
We donate billions to charities each year, yet much of our giving is ineffective. Why are we motivated to give but not to give effectively? Building off of evolutionary game theory models, we argue that donors evolved (biologically or culturally) to be insensitive to efficacy because efficacy is difficult to socially reward, as social rewards can only depend on well-defined and highly observable behaviors. We present five experiments testing key predictions of this account, predictions that are difficult to reconcile with alternative accounts based on cognitive or emotional limitations. Namely, we show that donors are more sensitive to efficacy when the decision is (i) not pro-social or (ii) affects kin. Moreover, (iii) social rewarders don’t condition on efficacy or (iv, v) other difficult-to-observe behaviors, like amount donated.
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Burum, B., & Hoffman, H. Reputations can explain the omission-commission distinction.
Central to moral judgment is the difference between acts of commission (killing) and those of omission (letting die). Omissions are judged less harshly even when intentions and outcomes are identical. We propose an explanation for this difference rooted in evolutionary game theory: it is easier to coordinate punishment in response to commissions because they leave more evidence of intent. Across five studies we provide two kinds of evidence for this explanation: (i) among observers, the omission-commission distinction is stronger for judgments related to punishing (which benefits from coordination) than for those related to avoidance (which can be done unilaterally); and (ii) among (hypothetical) actors, the omission-commission distinction is stronger for actions involving strangers than for those involving family members (with whom the threat of punishment presumably plays a smaller role).
Burum, B., Hoffman, H., & Cain, D. Reputations can explain strategic ignorance.
People will often avoid finding out information that would lead them to be more prosocial. Building off evolutionary game theory models, we argue that there is a social incentive to be strategically ignorant because plausible deniability hinders coordinated punishment. We demonstrate the presence of this incentive in four studies: (i) in a dictator game, third parties punish selfish dictators more if they know the other player's payoffs, compared to if they opt not to find out those payoffs; (ii) third parties believe it is worse to pass on an STI after being tested than after avoiding testing, (iii) third parties believe it is worse to buy inhumane chicken after finding out the details of the treatment than after avoiding these details; and (iv) third parties believe it is worse to buy clothing made with child labor after finding out about the labor practices than after avoiding this information. We also test two additional predictions of our account: (v) third parties distinguish less between strategic ignorance and knowing harm when it comes to avoidance, compared to punishment, and (vi) the tendency toward strategic ignorance is stronger for choices that affect others than for those that affect the self.
Malleability of Empathy
Burum, B., Hoffman, H. & Rand, D. Empathy tracks incentives to give.
Empathy encourages us to help, but it is both biased and malleable. We argue that this is because empathy tracks the incentives to help. We show this in two ways: (i) empathy increases (along with giving) when giving is observable to a trust game partner, and (ii) empathy decreases (along with giving) when giving is more financially costly.