Experts or Peers? The Influence of Different Social Endorsers on Reducing Sugar

1. EXPERTS OR PEERS? THE INFLUENCE OF DIFFERENT SOCIAL ENDORSERS ON REDUCING SUGAR CONSUMPTION

N. Arzumanyan1 , A.N. Shestakova1 , V. Moiseeva1 , V. Klucharev1 , I. Ntoumanis2
(1) National Research University Higher School of Economics, Moscow, Russian Federation
(2) Cook Children’s Health Care System, Fort Worth, United States

2. BACKGROUND

2
BACKGROUND
THERE ARE SEVERAL TYPES OF FOOD NUDGING
INTERVENTIONS:
COGNITIVELY-ORIENTED
AFFECTIVELY-ORIENTED
BEHAVIORALLY-ORIENTED
HEALTHY EATING CALLS – THE TYPE OF INTERVENTION,
WHERE THE PERSON IS DIRECTLY ENCOURAGED TO BE BETTER.
Cadario & Chandon, 2020

3. INFLUENCE OF SOCIAL NORMS ON FOOD CHOICES

BACKGROUND
INFLUENCE OF SOCIAL NORMS ON FOOD CHOICES
SOCIAL NORMS - ARE THE GUIDANCE FROM THE COMMUNITY ON THE PRINCIPLES AND
SUGGESTIONS ABOUT WHAT PEOPLE SHOULD EAT AND IN WHAT AMOUNTS.
THERE IS EVIDENCE THAT SOCIAL NORMS INDICATED BY THE MEMBER OF PERSON’S
REFERENT GROUP MIGHT BECOME MORE PERSUASIVE, AS WILL BE PERCEIVED AS
SOCIAL JUDGEMENTS (HIGGS, 2015).
TYPICAL CONSUMERS’ INFLUENCE MAY WORK THROUGH IDENTIFICATION BY VIRTUE OF
THEIR SIMILARITY TO THE CONSUMER, OR BY INTERNALIZATION SINCE SIMILARITY OF USAGE
MAY ENDOW THEM WITH SOME EXPERTISE FOR PRODUCTS WITH LITTLE INHERENT RISK
(FRIEDMAN & FRIEDMAN, 1979).
3

4. BACKGROUND

4
BACKGROUND
THE NTOUMANIS ET AL. (2022, 2023, 2024)
RESEARCH WAS EXAMINING THE INFLUENCE OF THE
EXPERT’S NARRATIVE ABOUT THE HARM OF EXCESSIVE
SUGAR CONSUMPTION ON THE PEOPLE’S
WILLINGNESS-TO-PAY (WTP) FOR SUGAR-FREE AND
SUGAR-CONTAINING PRODUCTS.
THE HEALTH EXPERT’S NARRATIVE DECREASED
INDIVIDUALS’ WTP FOR SUGAR-CONTAINING FOOD
* p < .05, ** p < .01, *** p < .001
Ntoumanis et al., 2023

5. RESEARCH HYPOTHESES

5
RESEARCH AIM - this research aims to investigate the comparative effectiveness of expert versus peer persuasion in
influencing food choices and willingness-to-pay for sugar-containing and sugar-free products. Its novelty is achieved through
testing the effect of expertise of the social endorser on the food choice which was not addressed in our previous iterations of
research.
RESEARCH HYPOTHESES
(H1) PEER PERSUASION CAN DECREASE THE WILLINGNESS-TO-PAY (WTP) FOR SUGAR-CONTAINING
FOOD
(H2) PEER PERSUASION WILL BE MORE EFFECTIVE AT REDUCING THE WTP FOR SUGAR-CONTAINING
FOOD COMPARED TO EXPERT PERSUASION

6. PARTICIPANTS

PARTICIPANTS
88 PARTICIPANTS
EXPERT CONDITION (N = 30, 18 FEMALES, MEAN AGE = 21.63 ± 2.79 YEARS)
PEER CONDITION (N = 29, 14 FEMALES, MEAN AGE = 21.41 ± 1.55 YEARS)
MULTIPLE PEERS CONDITION (N = 29, 15 FEMALES, MEAN AGE = 22.21 YEARS ± 3.65 YEARS)
6

7. STIMULI

STIMULI
CHARACTERISTICS
• NINETY PICTURES OF PRODUCTS – 30 FOR
EACH CONDITION
• EACH SUGAR-CONTAINING PRODUCT HAS A
SUGAR-FREE ALTERNATIVE
• ALL PRODUCTS ARE CURRENTLY
AVAILABLE ON THE MARKET
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8.

EXPERIMENTAL DESIGN
8
EXPERIMENTAL DESIGN
FIRST ITERATION OF THE BIDDING TASK
AUDIO HEALTHY EATING CALL
SECOND ITERATION OF THE BIDDING TASK
AUCTION
FIGURES
(A) THE SCHEMATIC REPRESENTATION OF THE EXPERIMENTAL PARADIGM.
(B) THE PROCEDURE OF ONE OF THE TRIALS IN THE BIDDING TASK.

9.

THE DESCRIPTION OF EXPERT AND PEER
CONDITIONS
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THE DESCRIPTION OF EXPERT AND PEER CONDITIONS
EXPERT CONDITION
PEER CONDITION
• DIETARY SPECIALIST –
• STUDENT – THE HOST OF THE
NUTRITIONIST
UNIVERSITY PODCAST
• THE ARGUMENTS USED IN BOTH CONDITIONS – EXPERT AND PEER – ARE THE SAME
(13 ARGUMENTS)
• THE DURATION OF BOTH AUDIO RECORDINGS DOES NOT DIFFER SIGNIFICANTLY (7
MINUTES)
MULTIPLE PEERS
CONDITION
THREE STUDENTS-FRIENDS
HEALTHY FOOD INTERVENTION WITH
MULTIPLE SOCIAL ENDORSERS
• THE NARRATIVE IN FORM OF TRIALOGUE –
3 NARRATORS
• THE PROFESSIONAL NARRATOR WHO RECORDED THE AUDIO VERSIONS OF BOTH
STORIES IS THE SAME
• DISCUSSION OF DIFFERENT ATTITUDES
TOWARDS SUGAR CONSUMPTION

10.

DATA ANALYSIS
10
DATA ANALYSIS
TO TEST OUR HYPOTHESIS (H1) THAT THE PEER PERSUASION WILL DECREASE THE
WTP FOR SUGAR-CONTAINING FOOD,
ONE-WAY REPEATED-MEASURES ANOVA: ΔWTP ~ PRODUCT CATEGORY
TO TEST OUR HYPOTHESIS (H2) THAT THE PEER PERSUASION WILL BE MORE
EFFECTIVE THAN THE EXPERT PERSUASION,
ΔWTP = WTP2 – WTP1 ,
TWO-WAY MIXED ANOVA: ΔWTP ~ PRODUCT CATEGORY * CONDITION
WHERE WTP1 IS THE WILLINGNESS-TO-PAY IN THE FIRST
ITERATION OF THE BIDDING TASK
AND WTP2 IS THE WILLINGNESS-TO-PAY IN THE SECOND
ITERATION OF THE BIDDING TASK

11.

RESULTS
RESULTS
(H1) BOTH PEER AND EXPERT PERSUASION DECREASE THE
WILLINGNESS-TO-PAY (WTP) FOR SUGAR-CONTAINING
FOOD
A SIMILAR TREND WAS OBSERVED IN ALL GROUPS
ALL SOCIAL ENDORSERS –
THE EXPERT (DOCTOR),
THE PEER (STUDENT),
THE GROUP OF MULTIPLE PEERS (STUDENTS-FRIENDS)
– INFLUENCED DECISION-MAKING AND LED TO A SIGNIFICANT
DECREASE IN WILLINGNESS-TO-PAY FOR SUGAR-CONTAINING PRODUCTS
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12.

CONCLUSION
12
CONCLUSION
• HEALTHY EATING CALL PROVIDED BY PEER CAN DECREASE WILLINGNESS-TO-PAY FOR SUGAR-CONTAINING
PRODUCTS
• THERE WAS NO SIGNIFICANT DIFFERENCE OUTLINED BETWEEN THE EFFECTIVENESS OF HEALTHY EATING CALL
PROVIDED BY DIFFERENT TYPES OF SOCIAL ENDORSERS – PEER OR EXPERT – BOTH DECREASE THE
WILLINGNESS-TO-PAY FOR FOOD PRODUCTS, THAT ARE SUGAR-CONTAINING

13. REFERENCES

13
REFERENCES
1.
Cadario, R., & Chandon, P. (2020). Which healthy eating nudges work best? A meta-analysis of field experiments. Marketing Science, 39(3), 465–
486.
2.
Friedman, H. H., & Friedman, L. (1979). Endorser effectiveness by product type. Journal of advertising research.
3.
Higgs, S. (2015). Social norms and their influence on eating behaviours. Appetite (Vol. 86, pp. 38–44). Academic Press.
4.
Ntoumanis, I., Davydova, A., Sheronova, J., Panidi, K., Kosonogov, V., Shestakova, A. N., Jääskeläinen, I. P., & Klucharev, V. (2023). Neural
mechanisms of expert persuasion on willingness to pay for sugar. Frontiers in Behavioral Neuroscience, 17.
5.
Ntoumanis, I., Panidi, K., Grebenschikova, Y., Shestakova, A. N., Kosonogov, V., Jääskeläinen, I. P., Kadieva, D., Baran, S., & Klucharev, V. (2022).
“Expert persuasion” can decrease willingness to pay for sugar-containing food. Frontiers in Nutrition, 9.
6.
Ntoumanis, I., Sheronova, J., Davydova, A., Dolgaleva, M., Jääskeläinen, I. P., Kosonogov, V., Shestakova, A.N., & Klucharev, V. (2024). Deciphering
the neural responses to a naturalistic persuasive message. Proceedings of the National Academy of Sciences, 121(43), e2401317121.
7.
Robinson, E., & Higgs, S. (2012). Liking Food Less: The Impact of Social Influence on Food Liking Evaluations in Female Students. PLoS ONE, 7(11).

14. CONTACTS

14
CONTACTS
Nina Arzumanyan, PhD student
email : ngarzumanyan@gmail.com
link to personal page : https://www.hse.ru/en/staff/ninarzum/