Intelligence and susceptibility to persuasion under conditions of active and passive participation

An experiment was conducted to test the prediction that verbal intelligence facilitates opinion change induced by active participation (improvising arguments). Seventy-one subjects were randomly assigned to improvise arguments or read persuasive messages advocating the same point of view (passive, control condition) about one of three topics. A short test of verbal intelligence was administered during the experiment; also, American College Test scores were obtained from the files of all subjects for whom they were available. Analysis of variance (with subjects partitioned into high and low intelligence groups) and correlational analyses supported the above prediction. There was some evidence that quality of the arguments improvised mediated the relationship between intelligence and opinion change, but the results were not totally consistent.