Psycholinguistic Experiments: A Case Study on Default Inferences in Philosophical Arguments—Analysing the Argument from Illusion

Experimental methods from psycholinguistics allow experimental philosophers to study important automatic inferences, with a view to explaining and assessing philosophically relevant intuitions and arguments. Philosophical thought is shaped by verbal reasoning in natural language. Such reasoning is driven by automatic comprehension inferences. Such inferences shape, e.g., intuitions about verbally described cases, in philosophical thought experiments; more generally, they shape moves from premises to conclusions in philosophical arguments. These inferences can be examined with questionnaire-based and eye-tracking methods from psycholinguistics. We explain how these methods can be adapted for use in experimental philosophy. We demonstrate their application by presenting a new eye-tracking study that helps assess the influential philosophical ``argument from illusion.'' The study examines whether stereotypical inferences from polysemous words (viz., appearance verbs) are automatically triggered even when prefaced by contexts that defeat the inferences. We use this worked example to explain the key conceptual steps involved in designing behavioural experiments, step by step. Going beyond the worked example, we also explain methods that require no laboratory facilities.