Psychologists and philosophers who pose moral dilemmas to understand moral judgment typically specify outcomes as certain to occur in them. This contrasts with real-life moral decision-making, which is almost always infused with probabilities (e.g., the probability of a given outcome if an action is or is not taken). Seven studies examine sensitivity to the size and location of shifts in probabilities of outcomes that would result from action in moral dilemmas. We find that moral judgments differ between actions that result (...) in an equal increase in probability of harm (equal size), but have different end-states (e.g., an increase in harm probability from 25% to 50% or from 50% to 75%). This deviation from expected value is robust under separate evaluation, and increases when the comparison between shifts is made explicit under simultaneous evaluation. Consistent with the centrality of perceived harm in some models of moral judgment, perceived harm partially mediates sensitivity to location of harm probability shift. Unlike for shifts in harm probabilities, participants are insensitive to the location of shifts in probability of beneficial outcomes. They are also insensitive to the location of shifts in probability of analogous monetary losses and gains, suggesting an asymmetry between harm and benefit in moral reasoning, as well as an asymmetry between moral and monetary decision-making more broadly. Implications for normative philosophical theory and moral psychological theory, as well as practical applications, are discussed. (shrink)

Oaksford & Chater's (O&C's) account of deductive reasoning is parsimonious at a local level (because a rational model is used to explain a wide range of behavior) and at a global level (because their Bayesian approach connects to other areas of research). Their emphasis on environmental structure is especially important, and the power of their approach is seen at both the computational and algorithmic levels.

For a variety of reasons, including the common use of deception in psychology experiments, participants often disbelieve experimenters' assertions about important task parameters. This can lead researchers to conclude incorrectly that participants are behaving non- normatively. The problem can be overcome by deriving and testing normative models that do not assume full belief in key task parameters. A real experimental example is discussed.

Any instance (i.e., event, behavior, trait) belongs to infinitely many reference classes, hence there are infinitely many base rates from which to choose. People clearly do not entertain all possible reference classes, however, so something must be limiting the search space. We suggest some possible mechanisms that determine which reference class is evoked for the purpose of judgment and decision.

The normative principle of description invariance presupposes that rational preferences must be complete. The completeness axiom is normatively dubious, however, and its rejection opens the door to rational framing effects. In this commentary, we suggest that Bermúdez's insightful challenge to the standard normative view of framing can be clarified and extended by situating it within a broader critique of completeness.