Immunization of a controverted belief through group discussion

An extension of McGuire's inoculation theory, from the area of cultural truisms to the realm of controverted beliefs, was investigated by manipulating previous attack as part of a group discussion situation in which actual defense of an issue was considered essential for having an inoculating effect. Results (p < 0.05) favored the main hypothesis when group 1 (requiring defense in response to a written verbal attack) was compared with the control group, but there were no significant differences between group 1 and group 2 (requiring discussion but no defense since there was no verbal attack).