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Conditioning unfamiliar and familiar flavours to specific positive emotions
Food Quality and Preference 21 (2010) 1105–1107
Contents lists available at ScienceDirect
Food Quality and Preference journal homepage: www.elsevier.com/locate/foodqual
Conditioning unfamiliar and familiar flavours to specific positive emotions J. Kuenzel a, E.H. Zandstra a,⇑, R. Lion a, I. Blanchette b, A. Thomas a, W. El-Deredy b a b
Unilever R&D Vlaardingen, The Netherlands University of Manchester, Manchester, UK
a r t i c l e
i n f o
Article history: Received 29 September 2009 Accepted 7 September 2010
Keywords: Emotions Conditioning Flavour
a b s t r a c t Emotions play an important role in determining food preferences and liking. We often speak of food as something that evokes emotions, such as comfort food. In two studies we investigated whether novel and familiar flavoured drinks could be conditioned to evoke specific positive emotions and whether this had a subsequent effect on liking of the drinks. In the first study, 167 participants consumed one of two novel flavoured drinks (one initially highly liked, one initially medium liked) for five consecutive days while watching film clips evoking either joy, contentment or no emotion in a between subjects design. On the test day, we measured whether the emotions from the film clips were transferred to the drink, i.e. that the drink (which has no active ingredients) on its own induced a joyful/ activating or contented/relaxed response. Behavioural measures showed that the conditioned drinks successfully induced the distinct positive emotions. Further, the emotional associations impacted on the liking of the drink. Liking scores for identical stimuli were different based on which emotion the drinks were associated with. In the second study with 139 participants, the same paradigm was used with familiar flavours. No emotional conditioning effects were found. These results suggest that it is possible to induce specific positive emotions by flavour conditioning in the absence of active ingredients for novel but not for familiar flavours, confirming that existing associations cannot be easily erased by new conditioning. Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction Foods and drinks are often associated with emotions (Desmet & Schifferstein, 2008; Gibson, 2006; King & Meiselman, 2010; Winkielman, Berridge, & Wilbarger, 2005). While the aim of many previous studies has been to measure food-related emotions that are already established (emotions associated with various food products such as pizza, savoury snacks, chocolate, pasta meals), our study focuses on establishing new associations between specific positive emotions (i.e. joy and contentment) and specific drinks, using an emotional conditioning paradigm (De Houwer, 2007). Emotional conditioning refers to the connection of a previously neutral stimulus (conditioned stimulus, CS) to an emotional reaction (conditioned reaction, CR) by pairing it with a stimulus (unconditioned stimulus, UCS) that evokes the target emotion (unconditioned reaction, UCR) (Watson & Rayner, 1920). Emotional conditioning has mainly been carried out with negative stimuli such as fear (Domjan, 2005). The second aim of our study was to establish whether connecting specific positive emotions with a product would change liking. This has not been investigated before and we therefore selected ⇑ Corresponding author. E-mail address: [email protected] (E.H. Zandstra). 0950-3293/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodqual.2010.09.003
drinks before the start of the study that were initially moderately/neutrally liked and initially highly liked to enable an increase or decrease in liking during the conditioning period. The third aim of the study was to see whether emotional conditioning would occur for unfamiliar flavours (experiment I) and familiar flavours (experiment II). Previous research (Shimp, Stuart, & Engle, 1991) suggests that, due to already existing associations with the drinks, conditioning new emotions to familiar drinks should be more difficult than conditioning the same emotions to unfamiliar (and therefore still association-free) drinks. 2. Experiment 1 2.1. Method 2.1.1. Participants and design Two hundred and sixteen participants (72 men; mean age 26 ± 5.6 years) were randomly allocated to one of six conditions in a 3 (Emotion: Joy vs. Contentment vs. Control) 2 (Drink: Highly liked vs. Moderately liked) between subject design. Of the 167 participants who completed all aspects of the study, 43 were in the control group (24 drank the moderately liked flavour ‘M’ and 19 the highly liked flavour ‘H’), 51 in the Contentment group (30 ‘M’, 21 ‘H’) and 72 in the Joy group (34 ‘M’, 38 ‘H’).
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J. Kuenzel et al. / Food Quality and Preference 21 (2010) 1105–1107
2.2. Materials 2.2.1. Film clips Short (4-5 min) film clips were used. Joy was induced by comedy scenes from movies and classic cartoons. Contentment was induced using clips from commercial relaxation videos. In the Control condition we used technical documentaries and weather reports. 2.2.2. Flavoured drinks Two novel flavoured drinks provided by International Flavors and Fragrances (IFF, NL) were used: one highly liked flavour (henceforth labelled ‘H’) and one moderately/neutrally liked flavour (henceforth labelled ‘M’). These drinks were selected on the basis of a pilot study with participants who did not take part in the main study. The clear, uncoloured drinks did not differ in energy content (28.5 kcal/100 ml). The drinks were served at 14 °C in 180 ml portions in unlabelled clear plastic cups. 2.3. Procedure For five consecutive days, participants came to the laboratory and were served the drinks just before the start of the film clip. They were asked to drink it completely while watching the film. Liking scores were collected after the third session. On the test day (two days after the final conditioning session) participants were again served the drink however no films were shown. Instead, participants were asked to consume the drinks while performing the tasks described in the following sections. 2.4. Dependent measures 2.4.1. Activity The two emotions measured were joy and contentment. Joy (or happiness) has been associated with being active (Fredrickson, 2000; Frijda, 1986) while contentment has been described as a relaxed and quiet state free of conflict (Davitz, 1969). It has also been described as less active than joy (Fredrickson, 2000; Frijda, 1986). Since level of activity experienced seems to be a key distinction between the two emotions, we decided to use this as our main dependent measure. We created an ‘‘Intuitive Language Test”, based on an implicit task originally developed by Murphy and Zajonc (1993). The task involves presenting characters from a language unknown to the participants (in the original study Chinese characters) as ambiguous stimuli. In the absence of any other clues, participants have to rely on their internal state to rate the meaning of the ambiguous stimuli. Because Chinese characters were familiar to a large minority of our participants, we used seven rotated and inverted symbols from languages unknown to all participants. Participants were told each symbol describes a verb and were asked to guess and rate how active that verb was on a 10point scale ranging from 1 (not active at all) to 10 (very active). 2.4.2. Liking Participants rated how much they liked the drink on a 5-point scale ranging from -2 (dislike it a lot) to + 2 (like it a lot).
Fig. 1. Mean score of liking (+1 SE) for the three different emotions and the two different drinks from 2 (dislike it a lot) to 2 (like it a lot).
F (1, 160) = .24, ns. The Emotion x Drink interaction was also nonsignificant, F (2, 160) = 1.12, ns. LSD post-hoc comparisons showed that participants rated the characters to be significantly more active in the joy condition than in both the contentment and the control conditions. 2.5.2. Flavour liking scores during conditioning We conducted a 3 (Condition: Joy, Contentment, Control) X 2 (Drink: M, H) ANOVA on liking scores. We found a main effect for Drink, F(1, 160) = 14.29, p < .001, no main effect for Emotion, F(2, 160) = 0.12, ns, and an interaction effect of Drink x Emotion, F(2, 160) = 4.37, p < .05. The pattern of results is presented in Fig. 1. Post-hoc LSD tests showed that the highly liked drink was liked significantly more in the Control than in the Contentment condition (p < .05). All other differences did not reach significance. 3. Experiment 2 3.1. Method 3.1.1. Participants and Design One hundred and ninety two participants (82 men; mean age 22.0 ± 3.7 years) were recruited of which 149 participants completed the experiment. Experiment II followed the same protocol as Experiment I. Forty two participants were in the Joy group (24 drank the cold drink, 18 the hot drink), 57 in the Contentment group (32 cold drink, 25 hot drink) and 50 in the Control group (23 cold drink, 27 hot drink). 3.2. Material
2.5. Results
3.2.1. Film clips As in experiment I short (4-5 min) film clips were used.
2.5.1. Activity Mean activity ratings for the first two symbols in the Intuitive Language Test was analyzed (only the first two symbols were used since participants develop strategies while doing the task and therefore the implicit element is lost). A 3 (Emotions: Joy, Contentment, Control) x 2 (Drink: ‘H’, ‘M’) ANOVA revealed a main effect of Emotion, F (2, 160) = 6.95; p < .001, but no effect of Drink,
3.2.2. Flavoured drinks As familiar flavoured drink, we used one drink –ice tea– and served it at different temperatures to ensure an equal nutritional value. The ice tea drink was served hot at 52 °C in the ‘Hot drink’ group and cold at 14 °C in the ‘Cold drink’ group. Also, we assumed that hot tea would be more closely associated with contentment and cold tea with joy and energy. During recruitment, every
J. Kuenzel et al. / Food Quality and Preference 21 (2010) 1105–1107
participant rated both drinks. Participants were allocated to their preferred drink. Each participant was served 180 ml of the drink in a white Styrofoam cup. 3.3. Procedure The procedure used in Experiment II was similar to the one used in Experiment I. The only differences were that participants only came to three conditioning sessions, and they were asked to rate the liking of their respective drinks after each session, rather than only once as in Experiment I. 3.4. Dependent Measures Dependent measures used in this study were identical to the ones in Experiment I. 3.5. Results 3.5.1. Activity A 3 (Emotions: Joy, Contentment, Control) x 2 (Drink: hot, cold) ANOVA on the mean activity ratings for the first two symbols revealed no main effect of Emotion, F (2, 139) = 1.45, ns, but an effect of Drink Type, F (1, 139) = 4.57, p < .05. The Emotion x Drink interaction was not significant, F (2, 139) = 0.28, ns. 3.5.2. Flavour liking scores during conditioning A mixed ANOVA on the liking scores with day of conditioning (first day, second day, third day) as within subject factor and emotion (joy, contentment, control) and drink (hot, cold) as between subject factors was conducted. No significant differences were found, F’s < 2.70, ns. 4. Discussion The present study showed that it is possible to induce specific positive emotions (here joy and contentment) for specific flavours through emotional conditioning even in the absence of active ingredients. This however was possible for novel but not for familiar flavours. This confirms that existing associations cannot be easily erased by new conditioning. A remarkable finding was that the emotion conditioning produced differential effects on the liking of the drinks. These differential effects depended on the type of emotion evoked, i.e. whether the stimulus evoked contentment or joy. The highly liked drink was actually less liked in both emotional conditions compared to the control condition, while the originally moderately liked drink showed a tendency to be more liked in both emotional conditions than the control condition. A possible reason for this effect is that while experiencing emotions, attention is divided. Divided attention could lead the liking of the drinks to be scored towards the middle, i.e. higher liking scores for the moderately liked drink and lower ones for the highly liked drink. This result highlights the importance of the nature of the UCS – in this case the kind of emotion evoked by the UCS – in evaluative conditioning experiments. Although all of the UCSs were positive, they differed in other aspects (e.g., activity), which led to different effects. This result highlights the importance of choosing specific UCS in evaluative conditioning, and may explain why evaluative flavour conditioning effects tend to be unreliable with positive stimuli (De Houwer, Thomas, & Baeyens, 2001). It is likely that stimuli evoking different specific positive emotions lead to different strengths of evaluative conditioning effects. A clear finding was that conditioning specific positive emotions to familiar flavours is not readily acquired or expressed under
1107
these conditions. This confirms findings from previous research on conditioning. Classical and evaluative conditioning has been shown to be less effective for familiar stimuli (Cacioppo, Marshall-Goodell, Tassinary, & Petty, 1992; Shimp et al., 1991; Gibson, 2006). Furthermore, Köster has shown that flavour-emotion combinations are highly learned (Köster, 2003). It is possible that for the unfamiliar flavours, where no associations exist, there is still an opportunity to create a new flavour-emotion combination. By contrast, for familiar flavours existing emotional associations would have to be overcome before observing a conditioning effect. Three pairings of the UC and the CS were probably too few under these circumstances, even though each of the pairing lasted for several minutes and included various sips of the drink. A possible caveat to both studies is the possibility that emotions may not have been transferred to the drinks, but to the location where the experiment was conducted. The drinks in the test session were consumed at the same time and at the same place as where the conditioning took place during the first week. Also, it would have been desirable to run the experiment by using a within-subject design. However, the length of the UCS (5 minutes) and the amount of beverage to be consumed (180 ml) limited the number of combinations that could be run within one session. In summary, the results show that it is possible to condition specific positive emotions, provided unfamiliar CSs are used. Furthermore, where previous research has shown that general positive affect can be conditioned to a given flavour and therefore increase liking of this flavour, our results go beyond this. Not only did we condition specific emotions, we also showed effects on liking that go beyond the evaluative conditioning paradigm; the specific emotions used as UCS seemed to moderate the strength of the evaluative conditioning effect. This experiment provides a first indication that emotional conditioning with specific positive emotions is possible. Future studies have to show how stable these effects are, whether they depend on the product used, and how strongly both emotional and evaluative conditioning contribute to them. References Cacioppo, J. T., Marshall-Goodell, B. S., Tassinary, L. G., & Petty, R. (1992). Rudimentary determinants of attitudes: Classical conditioning is more effective when prior knowledge about the attitude stimulus is low than high. Journal of Experimental Social Psychology, 28, 207–233. Houwer, De. (2007). A conceptual and theoretical analysis of evaluative conditioning. Spanish Journal of Psychology, 10, 230–241. 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, 127, 853–869. Davitz, J. (1969). The Language of Emotions. New York: Academic Press. Desmet, P. M. A., & Schifferstein, H. N. J. (2008). Sources of positive and negative emotions in food experience. Appetite, 50(2–3), 290–301. Domjan, M. (2005). Pavlovia conditioning: A functional perspective. Annual Review of Psychology, 56, 179–206. Fredrickson, B. L. (2000). Cultivating positive emotions to optimise health and wellbeing. Prevention & Treatment, 3, 0001a. Frijda, N. H. (1986). The Emotions. Cambridge: Cambridge University Press. Gibson, E. L. (2006). Emotional influence on food choice. Sensory, physiological and psychological pathways. Physiology and Behaviour, 89, 53–61. King, S. C., & Meiselman, H. L. (2010). Development of a method to measure consumer emotions associated with foods. Food Quality and Preference, 21(2), 168–177. Köster, E. P. (2003). The psychology of food choice. some often encountered fallacies. Food Quality and Preference, 14, 259–373. Murphy, S. T., & Zajonc, R. B. (1993). Affect, cognition, and awareness: Affective priming with optimal and suboptimal stimulus exposures. Journal of Personality and Social Psychology, 64, 723–739. Shimp, T. A., Stuart, E. W., & Engle, R. W. (1991). A program of classical conditioning experiments testing variation in the conditioned stimulus and context. Journal of Consumer Research, 18(1), 1–12. Watson, J. B., & Rayner, R. (1920). Conditioned emotional reactions. Journal of Experimental Psychology, 3, 1–14. Winkielman, P., Berridge, K. C., & Wilbarger, J. (2005). Unconscious affective reactions to masked happy versus angry faces influence consumption behavior and judgments of value. Personality and Social Psychology Bulletin, 1, 121–135.
Contents lists available at ScienceDirect
Food Quality and Preference journal homepage: www.elsevier.com/locate/foodqual
Conditioning unfamiliar and familiar flavours to specific positive emotions J. Kuenzel a, E.H. Zandstra a,⇑, R. Lion a, I. Blanchette b, A. Thomas a, W. El-Deredy b a b
Unilever R&D Vlaardingen, The Netherlands University of Manchester, Manchester, UK
a r t i c l e
i n f o
Article history: Received 29 September 2009 Accepted 7 September 2010
Keywords: Emotions Conditioning Flavour
a b s t r a c t Emotions play an important role in determining food preferences and liking. We often speak of food as something that evokes emotions, such as comfort food. In two studies we investigated whether novel and familiar flavoured drinks could be conditioned to evoke specific positive emotions and whether this had a subsequent effect on liking of the drinks. In the first study, 167 participants consumed one of two novel flavoured drinks (one initially highly liked, one initially medium liked) for five consecutive days while watching film clips evoking either joy, contentment or no emotion in a between subjects design. On the test day, we measured whether the emotions from the film clips were transferred to the drink, i.e. that the drink (which has no active ingredients) on its own induced a joyful/ activating or contented/relaxed response. Behavioural measures showed that the conditioned drinks successfully induced the distinct positive emotions. Further, the emotional associations impacted on the liking of the drink. Liking scores for identical stimuli were different based on which emotion the drinks were associated with. In the second study with 139 participants, the same paradigm was used with familiar flavours. No emotional conditioning effects were found. These results suggest that it is possible to induce specific positive emotions by flavour conditioning in the absence of active ingredients for novel but not for familiar flavours, confirming that existing associations cannot be easily erased by new conditioning. Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction Foods and drinks are often associated with emotions (Desmet & Schifferstein, 2008; Gibson, 2006; King & Meiselman, 2010; Winkielman, Berridge, & Wilbarger, 2005). While the aim of many previous studies has been to measure food-related emotions that are already established (emotions associated with various food products such as pizza, savoury snacks, chocolate, pasta meals), our study focuses on establishing new associations between specific positive emotions (i.e. joy and contentment) and specific drinks, using an emotional conditioning paradigm (De Houwer, 2007). Emotional conditioning refers to the connection of a previously neutral stimulus (conditioned stimulus, CS) to an emotional reaction (conditioned reaction, CR) by pairing it with a stimulus (unconditioned stimulus, UCS) that evokes the target emotion (unconditioned reaction, UCR) (Watson & Rayner, 1920). Emotional conditioning has mainly been carried out with negative stimuli such as fear (Domjan, 2005). The second aim of our study was to establish whether connecting specific positive emotions with a product would change liking. This has not been investigated before and we therefore selected ⇑ Corresponding author. E-mail address: [email protected] (E.H. Zandstra). 0950-3293/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodqual.2010.09.003
drinks before the start of the study that were initially moderately/neutrally liked and initially highly liked to enable an increase or decrease in liking during the conditioning period. The third aim of the study was to see whether emotional conditioning would occur for unfamiliar flavours (experiment I) and familiar flavours (experiment II). Previous research (Shimp, Stuart, & Engle, 1991) suggests that, due to already existing associations with the drinks, conditioning new emotions to familiar drinks should be more difficult than conditioning the same emotions to unfamiliar (and therefore still association-free) drinks. 2. Experiment 1 2.1. Method 2.1.1. Participants and design Two hundred and sixteen participants (72 men; mean age 26 ± 5.6 years) were randomly allocated to one of six conditions in a 3 (Emotion: Joy vs. Contentment vs. Control) 2 (Drink: Highly liked vs. Moderately liked) between subject design. Of the 167 participants who completed all aspects of the study, 43 were in the control group (24 drank the moderately liked flavour ‘M’ and 19 the highly liked flavour ‘H’), 51 in the Contentment group (30 ‘M’, 21 ‘H’) and 72 in the Joy group (34 ‘M’, 38 ‘H’).
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J. Kuenzel et al. / Food Quality and Preference 21 (2010) 1105–1107
2.2. Materials 2.2.1. Film clips Short (4-5 min) film clips were used. Joy was induced by comedy scenes from movies and classic cartoons. Contentment was induced using clips from commercial relaxation videos. In the Control condition we used technical documentaries and weather reports. 2.2.2. Flavoured drinks Two novel flavoured drinks provided by International Flavors and Fragrances (IFF, NL) were used: one highly liked flavour (henceforth labelled ‘H’) and one moderately/neutrally liked flavour (henceforth labelled ‘M’). These drinks were selected on the basis of a pilot study with participants who did not take part in the main study. The clear, uncoloured drinks did not differ in energy content (28.5 kcal/100 ml). The drinks were served at 14 °C in 180 ml portions in unlabelled clear plastic cups. 2.3. Procedure For five consecutive days, participants came to the laboratory and were served the drinks just before the start of the film clip. They were asked to drink it completely while watching the film. Liking scores were collected after the third session. On the test day (two days after the final conditioning session) participants were again served the drink however no films were shown. Instead, participants were asked to consume the drinks while performing the tasks described in the following sections. 2.4. Dependent measures 2.4.1. Activity The two emotions measured were joy and contentment. Joy (or happiness) has been associated with being active (Fredrickson, 2000; Frijda, 1986) while contentment has been described as a relaxed and quiet state free of conflict (Davitz, 1969). It has also been described as less active than joy (Fredrickson, 2000; Frijda, 1986). Since level of activity experienced seems to be a key distinction between the two emotions, we decided to use this as our main dependent measure. We created an ‘‘Intuitive Language Test”, based on an implicit task originally developed by Murphy and Zajonc (1993). The task involves presenting characters from a language unknown to the participants (in the original study Chinese characters) as ambiguous stimuli. In the absence of any other clues, participants have to rely on their internal state to rate the meaning of the ambiguous stimuli. Because Chinese characters were familiar to a large minority of our participants, we used seven rotated and inverted symbols from languages unknown to all participants. Participants were told each symbol describes a verb and were asked to guess and rate how active that verb was on a 10point scale ranging from 1 (not active at all) to 10 (very active). 2.4.2. Liking Participants rated how much they liked the drink on a 5-point scale ranging from -2 (dislike it a lot) to + 2 (like it a lot).
Fig. 1. Mean score of liking (+1 SE) for the three different emotions and the two different drinks from 2 (dislike it a lot) to 2 (like it a lot).
F (1, 160) = .24, ns. The Emotion x Drink interaction was also nonsignificant, F (2, 160) = 1.12, ns. LSD post-hoc comparisons showed that participants rated the characters to be significantly more active in the joy condition than in both the contentment and the control conditions. 2.5.2. Flavour liking scores during conditioning We conducted a 3 (Condition: Joy, Contentment, Control) X 2 (Drink: M, H) ANOVA on liking scores. We found a main effect for Drink, F(1, 160) = 14.29, p < .001, no main effect for Emotion, F(2, 160) = 0.12, ns, and an interaction effect of Drink x Emotion, F(2, 160) = 4.37, p < .05. The pattern of results is presented in Fig. 1. Post-hoc LSD tests showed that the highly liked drink was liked significantly more in the Control than in the Contentment condition (p < .05). All other differences did not reach significance. 3. Experiment 2 3.1. Method 3.1.1. Participants and Design One hundred and ninety two participants (82 men; mean age 22.0 ± 3.7 years) were recruited of which 149 participants completed the experiment. Experiment II followed the same protocol as Experiment I. Forty two participants were in the Joy group (24 drank the cold drink, 18 the hot drink), 57 in the Contentment group (32 cold drink, 25 hot drink) and 50 in the Control group (23 cold drink, 27 hot drink). 3.2. Material
2.5. Results
3.2.1. Film clips As in experiment I short (4-5 min) film clips were used.
2.5.1. Activity Mean activity ratings for the first two symbols in the Intuitive Language Test was analyzed (only the first two symbols were used since participants develop strategies while doing the task and therefore the implicit element is lost). A 3 (Emotions: Joy, Contentment, Control) x 2 (Drink: ‘H’, ‘M’) ANOVA revealed a main effect of Emotion, F (2, 160) = 6.95; p < .001, but no effect of Drink,
3.2.2. Flavoured drinks As familiar flavoured drink, we used one drink –ice tea– and served it at different temperatures to ensure an equal nutritional value. The ice tea drink was served hot at 52 °C in the ‘Hot drink’ group and cold at 14 °C in the ‘Cold drink’ group. Also, we assumed that hot tea would be more closely associated with contentment and cold tea with joy and energy. During recruitment, every
J. Kuenzel et al. / Food Quality and Preference 21 (2010) 1105–1107
participant rated both drinks. Participants were allocated to their preferred drink. Each participant was served 180 ml of the drink in a white Styrofoam cup. 3.3. Procedure The procedure used in Experiment II was similar to the one used in Experiment I. The only differences were that participants only came to three conditioning sessions, and they were asked to rate the liking of their respective drinks after each session, rather than only once as in Experiment I. 3.4. Dependent Measures Dependent measures used in this study were identical to the ones in Experiment I. 3.5. Results 3.5.1. Activity A 3 (Emotions: Joy, Contentment, Control) x 2 (Drink: hot, cold) ANOVA on the mean activity ratings for the first two symbols revealed no main effect of Emotion, F (2, 139) = 1.45, ns, but an effect of Drink Type, F (1, 139) = 4.57, p < .05. The Emotion x Drink interaction was not significant, F (2, 139) = 0.28, ns. 3.5.2. Flavour liking scores during conditioning A mixed ANOVA on the liking scores with day of conditioning (first day, second day, third day) as within subject factor and emotion (joy, contentment, control) and drink (hot, cold) as between subject factors was conducted. No significant differences were found, F’s < 2.70, ns. 4. Discussion The present study showed that it is possible to induce specific positive emotions (here joy and contentment) for specific flavours through emotional conditioning even in the absence of active ingredients. This however was possible for novel but not for familiar flavours. This confirms that existing associations cannot be easily erased by new conditioning. A remarkable finding was that the emotion conditioning produced differential effects on the liking of the drinks. These differential effects depended on the type of emotion evoked, i.e. whether the stimulus evoked contentment or joy. The highly liked drink was actually less liked in both emotional conditions compared to the control condition, while the originally moderately liked drink showed a tendency to be more liked in both emotional conditions than the control condition. A possible reason for this effect is that while experiencing emotions, attention is divided. Divided attention could lead the liking of the drinks to be scored towards the middle, i.e. higher liking scores for the moderately liked drink and lower ones for the highly liked drink. This result highlights the importance of the nature of the UCS – in this case the kind of emotion evoked by the UCS – in evaluative conditioning experiments. Although all of the UCSs were positive, they differed in other aspects (e.g., activity), which led to different effects. This result highlights the importance of choosing specific UCS in evaluative conditioning, and may explain why evaluative flavour conditioning effects tend to be unreliable with positive stimuli (De Houwer, Thomas, & Baeyens, 2001). It is likely that stimuli evoking different specific positive emotions lead to different strengths of evaluative conditioning effects. A clear finding was that conditioning specific positive emotions to familiar flavours is not readily acquired or expressed under
1107
these conditions. This confirms findings from previous research on conditioning. Classical and evaluative conditioning has been shown to be less effective for familiar stimuli (Cacioppo, Marshall-Goodell, Tassinary, & Petty, 1992; Shimp et al., 1991; Gibson, 2006). Furthermore, Köster has shown that flavour-emotion combinations are highly learned (Köster, 2003). It is possible that for the unfamiliar flavours, where no associations exist, there is still an opportunity to create a new flavour-emotion combination. By contrast, for familiar flavours existing emotional associations would have to be overcome before observing a conditioning effect. Three pairings of the UC and the CS were probably too few under these circumstances, even though each of the pairing lasted for several minutes and included various sips of the drink. A possible caveat to both studies is the possibility that emotions may not have been transferred to the drinks, but to the location where the experiment was conducted. The drinks in the test session were consumed at the same time and at the same place as where the conditioning took place during the first week. Also, it would have been desirable to run the experiment by using a within-subject design. However, the length of the UCS (5 minutes) and the amount of beverage to be consumed (180 ml) limited the number of combinations that could be run within one session. In summary, the results show that it is possible to condition specific positive emotions, provided unfamiliar CSs are used. Furthermore, where previous research has shown that general positive affect can be conditioned to a given flavour and therefore increase liking of this flavour, our results go beyond this. Not only did we condition specific emotions, we also showed effects on liking that go beyond the evaluative conditioning paradigm; the specific emotions used as UCS seemed to moderate the strength of the evaluative conditioning effect. This experiment provides a first indication that emotional conditioning with specific positive emotions is possible. Future studies have to show how stable these effects are, whether they depend on the product used, and how strongly both emotional and evaluative conditioning contribute to them. References Cacioppo, J. T., Marshall-Goodell, B. S., Tassinary, L. G., & Petty, R. (1992). Rudimentary determinants of attitudes: Classical conditioning is more effective when prior knowledge about the attitude stimulus is low than high. Journal of Experimental Social Psychology, 28, 207–233. Houwer, De. (2007). A conceptual and theoretical analysis of evaluative conditioning. Spanish Journal of Psychology, 10, 230–241. 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, 127, 853–869. Davitz, J. (1969). The Language of Emotions. New York: Academic Press. Desmet, P. M. A., & Schifferstein, H. N. J. (2008). Sources of positive and negative emotions in food experience. Appetite, 50(2–3), 290–301. Domjan, M. (2005). Pavlovia conditioning: A functional perspective. Annual Review of Psychology, 56, 179–206. Fredrickson, B. L. (2000). Cultivating positive emotions to optimise health and wellbeing. Prevention & Treatment, 3, 0001a. Frijda, N. H. (1986). The Emotions. Cambridge: Cambridge University Press. Gibson, E. L. (2006). Emotional influence on food choice. Sensory, physiological and psychological pathways. Physiology and Behaviour, 89, 53–61. King, S. C., & Meiselman, H. L. (2010). Development of a method to measure consumer emotions associated with foods. Food Quality and Preference, 21(2), 168–177. Köster, E. P. (2003). The psychology of food choice. some often encountered fallacies. Food Quality and Preference, 14, 259–373. Murphy, S. T., & Zajonc, R. B. (1993). Affect, cognition, and awareness: Affective priming with optimal and suboptimal stimulus exposures. Journal of Personality and Social Psychology, 64, 723–739. Shimp, T. A., Stuart, E. W., & Engle, R. W. (1991). A program of classical conditioning experiments testing variation in the conditioned stimulus and context. Journal of Consumer Research, 18(1), 1–12. Watson, J. B., & Rayner, R. (1920). Conditioned emotional reactions. Journal of Experimental Psychology, 3, 1–14. Winkielman, P., Berridge, K. C., & Wilbarger, J. (2005). Unconscious affective reactions to masked happy versus angry faces influence consumption behavior and judgments of value. Personality and Social Psychology Bulletin, 1, 121–135.