In a recent post on the topic of food likes and dislikes, we explored the way food preferences can be affected by the proximity of something else that is liked or disliked. This phenomenon is called “evaluative conditioning.”
The relationship between flavor evaluative conditioning and contingency awareness was investigated in two experiments (Wardle et al., 2007). In both experiments evaluative conditioning was seen only in those participants who were aware of the contingencies. According to the researchers, the results of these experiments contradicted earlier findings, where evaluative conditioning occurred in participants who showed no awareness of the contingencies.
How did they research these issues and what did they find?
Experiment 1 was designed to replicate the evaluative conditioning effect reported by Baeyens et al. (1990) and Dickinson & Brown (2007), and to further explore whether or not it is possible to detect any level of contingency awareness at all in flavor evaluative conditioning.
To reiterate, findings by Baeyens et al. (1990) and Dickinson & Brown (2007) showed that evaluative conditioning occurred without awareness. In Experiment 1, a within-subjects design using two flavors as CSs were used. During conditioning, one flavor was always paired with sugar (positive US) and the other with a bitter tasting substance (negative US).
In the test phase, participants tasted the CS flavor and then completed the evaluative and contingency rating scales for the flavor before moving on to taste the next flavor.
The results showed evaluative conditioning occurred, and the participants liked the flavor that had been coupled with sugar more than the flavor coupled with the bitter substance. The awareness test revealed that only aware participants displayed evaluative conditioning.
The objective of Experiment 2 was to replicate the results of the first experiment. The main weakness of Experiment 1 was that the vanilla flavor used had a slight yellowish coloring that might have influenced participants’ answers given on the contingency test.
In Experiment 2, colorless flavors were used. The finding in Experiment 2 showed, as in Experiment 1, an evaluative conditioning effect, and only participants that showed awareness displayed evaluative conditioning. The findings of the two studies by Wardle et al. were inconsistent with those of Baeyens et al. (1990) and Dickinson & Brown (2007), studies that showed an evaluative conditioning effect in effect in the absence of awareness.
Wardle et al. (2007) pointed out that the previous studies showing evaluative conditioning in the absence of awareness were methodologically flawed. The main weakness in the Baeyens et al. (1990) study was that the measure of awareness was different in the testing and conditioning phases.
Another weakness was the measure of awareness was always administered after the evaluative test, which could have weakened participants’ ability to recall contingencies (lacked counterbalancing). Wardle et al. (2007) pointed out problems with the Dickinson & Brown (2007) study, including increased complexity due to presentation of four contingencies and an analysis of contingency awareness based on aggregate scores.
They suggested that basing awareness on aggregate scores might miss some contingency awareness for a subset of individual CSs, or a subset of participants. Further analysis of the data from the Dickinson & Brown (2007) study showed that the aggregate scores overlooked the fact that over a third of the participants in the experiment were aware of at least three of the four contingencies.
Baeyens, F., Eelen, P., & Van Den Bergh, O. (1990a). Contingency awareness in evaluative conditioning: A case for unaware affective-evaluative learning. Cognition & Emotion, 4, 3-18.
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.
Dickinson, A., & Brown, KJ. (2007). Flavor evaluative conditioning is unaffected by contingency knowledge during training with color-flavor compounds. Learning & Behavior, 35, 36-42.
Wardle, SG., Mitchell, CJ., & Lovibond, PF. (2007). Flavor evaluative conditioning and contingency awareness. Learning & Behavior, 35 (4), 233-241.
Carrot juice photo available at Shutterstock