Need for cognition and message complexity in motivating fruit and vegetable intake among callers to the cancer information service.

This field experiment examined the impact of an individual's need for cognition (NFC; the tendency to enjoy thinking deeply about issues), complex versus simple messages, and the interaction of NFC and message type on encouraging fruit and vegetable consumption. Callers to the Cancer Information Service of the National Cancer Institute (N=517) were asked to participate in the experiment at the end of their call. Individual NFC was assessed, and participants were assigned randomly to receive a telephone message promoting fruit and vegetable consumption that was either complex and multifaceted or simple and straightforward. Similarly constructed brochures were mailed immediately following the call, and additional brochures were mailed 2 and 3 months later. Although NFC did not predict intake, complex messages were more effective than simple messages in motivating fruit and vegetable consumption 1 and 4 months later.