Social Enhancement of Food Preferences in Norway Rats: A Brief Review
BENNETT G. GALEF, JR. Department of Psychology McMaster University Hamilton, Ontario Canada L8S 4K1
F or more than 25 years, my students, coworkers, and I have been engaged in experiments designed both to analyze the behavioral processes that permit one Norway rat (Rattus norvegicus) to influence another's selection of foods and to determine how such social influences might facilitate the development of adaptive feeding repertoires by free-living rats.
The relative ease with which social influences on selection of food by rats can be studied in the laboratory has made social transmission of food preferences in rats a particularly fruitful model system in which to study social-learning processes at all stages in the life cycle (For reviews see Galef, 1977, 1985b, 1988, 1994): odor- bearing chemicals in a rat dam's food enter her bloodstream and cross placental membranes to infiltrate the circulation of any fetuses she is carrying. Consequently, late in gestation, fetal rats can detect the scents of at least some of the foods that their dam has eaten and will respond positively to those foods shortly after birth (Hepper, 1988). A few days after parturition, when infant rats are still totally dependent on their dam for nutriment, they receive information through their____________________