Evaluative conditioning is defined as a change in liking, which occurs due to an association with a positive or negative stimulus (De Hower et al., 2001).
Simply put, this means that our preferences for brands, products, people and other things can be influenced and even modified by the presence of something we like or dislike strongly.
Evaluative conditioning has also been associated with the development of food likes and dislikes. Humans develop a dislike for foods that are followed by negative consequences such as nausea, rashes, diarrhea, and breathing problems (Pelchat & Rozin, 1982). Taste aversions are derived from various situations, such as food poisoning, allergic reactions, over consumption and some medical treatments (Batsell & Brown, 1998).
Although the majority of developed food aversions are attributed to the taste or flavor of food, a proportion of aversions are related to smell (de Silva & Rachman, 1987).
Change in food likes has been shown with flavor-flavor pairings: pairing of a neutral flavor (conditioned stimulus, or CS) with a liked or disliked flavor (unconditioned stimulus, or US) that can result in a change in liking of the CS flavor. Flavor-flavor conditioning appears to be a potent tool for increasing liking for isolated tastes and specific foods (Eertmans et al., 2001). Liking for unsweetened vegetables and unfamiliar teas increases after they have been consumed sweetened on a number of occasions (Eertmans et al., 2001; Capaldi, 1996). Willingness to try new foods increases after providing people with verbal information that the foods taste good. This may imply that flavor-flavor or food-flavor conditioning can also occur by using written messages (Pelchat & Pliner, 1995).
It has also been demonstrated that flavor-flavor conditioning can occur through observation (Baeyens et al., 1996). With observational evaluative conditioning, participants observe a social model being exposed to a CS-US association. The model tastes a food and shows his or her reaction by facial expression or other gestures. When observers rate the target stimulus after observing the model’s reaction an evaluative conditioning effect can be observed.
Baeyens and colleagues (1990) hypothesized that the pairing of a neutral flavor (CS) with an already liked (or disliked) flavor (US) should result in an increase (or decrease) in liking for the originally neutral flavor. Sugar was used as a positive US, and a bitter tasting substance as a negative US, the flavor of the drink served as the CS. An evaluative conditioning effect was observed in the flavor-flavor, negative condition. However, the evidence for positive flavor-flavor conditioning was weak at best. When children are presented neutral foods as rewards or the foods are paired with attention from adults, the food appears to produce increases in preference (Eertmans et al., 2001).
Evaluative conditioning has been proposed to occur in the presence and absence of awareness (Wardle et al., 2007). Evaluative conditioning and its relationship with awareness will be addressed in the next article: Change in Food Likes/Dislikes 2. Stay tuned for part two.
Baeyens, F., Eelen, P., Van den Bergh, O., & Crombez, G. (1990). Flavor-flavor and color-flavor conditioning in humans. Learning and Motivation, Vol. 21, Issue 4, Pages 434-455.
Batsell, WR., & Brown, AS. (1998). Human-flavor aversion conditioning: a comparison of traditional and cognitive aversions. Learning and Motivation, 29, 383-396.
Capaldi, ED. (1996). Conditioned food preferences. In Capaldi, E.D. (ed.) Why We Eat What We Eat: The Psychology of Eating. American Psychological Associaiton, Washington DC, pp. 53-80.
De Houwer, J., Thomas, S., & Baeyens, F. (2001). Associative Learning of Likes and Dislikes: A Review of 25 years of Research on Human Evaluative Conditioning. Psychological Bulletin, Vol. 127, No.6, 853-869.
De Silva, P., & Rachman, S. (1987). Human food aversions: nature and acquisition. Behavior, Research and Therapy, 25, 457-468.
Eertmans, A., Baeyens, F., & Van den Bergh, O. (2001). Food likes and their relative importance in human eating behavior: review and preliminary suggestions for health promotion. Health Education Research: Theory and Practice, Vol.16, No.4, pp. 443-456.
Pelchat, ML., & Pliner, P. (1995). “Try it You’ll like it’: effects of information on willingness to try novel foods. Appetite, 24, 153-166.
Pelchat, ML., & Rozin, P. (1982). The special role of nausea in the acquisition of food dislikes by humans. Appetite, 3, 341-351.
Wardle, SG., Mitchell, CJ., & Lovibond, PF. (2007). Flavor evaluative conditioning and contingency awareness. Learning & Behavior, 35 (4), 233-241.
Lettuce in a cone photo available from Shutterstock