A scientist interested in studying intelligence shows people…

A scientist interested in studying intelligence shows people a stimulus and then quickly takes it away. The scientist then does this repeatedly, with the stimulus shown for different amounts of time, to find out how much time is needed for the participant to correctly answer a question about the stimulus. People who can perform this task with very short durations are likely to:

There seems to be a correlation between schizophrenia and sm…

There seems to be a correlation between schizophrenia and smoking cigarettes. It may be the case that neither causes the other. Perhaps a separate factor, such as socioeconomic status, accounts best for both schizophrenia and cigarette smoking. This illustrates a problem in assessing causality that is specific to correlational research and is called __________.