Illusory inferences and conditionals
- by Sunny Khemlani
- in News
- posted May 12, 2024
Orlando Espino, Isabel Orenes, and Sergío Moren-Rios present new work on illusory conditional inferences, which is now out in print at Memory & Cognition. Their new analysis focuses on how people reason about both conditionals (“if A then B”), “only if” conditions (“only if A then B”), and biconditionals (“if and only if A then B”). It finds that people systematically produce illusory inferences, which the model theory predicts. It also presents an extension and refinement of the theory to explain how people distinguish between conditionals and biconditionals.
Here’s the abstract to their paper:
A robber points a gun at a cashier and says: “Only one of these two options is true: If you conceal the combination to the safe, then I kill you; otherwise, if you don´t conceal the combination to the safe, then I kill you.” Hearing this statement, most people conclude that, in either case, “I kill you.” This is an illusory response, in fact; the valid conclusion states “I don´t kill you.” The research reported here studied the roles that different expressions of conditionals (“if-then,” “only if,” and “if and only if”) play in the illusory response. Three experiments show that participants inferred the conclusion “I kill you” from the conditional “if-then” and “I may or may not kill you” from the conditional “only if,” while selecting both options with similar frequency for the biconditional “if and only if.” These results shed light on the main theories of deductive reasoning.