Scientists Show That Peer Influence Can Be as Effective as Expert Advice

Eating habits can be shaped not only by the authority of medical experts but also through ordinary conversations among friends. Researchers at HSE University have shown that advice from peers to reduce sugar consumption is just as effective as advice from experts. The study's findings have been published in Frontiers in Nutrition.
Excessive sugar consumption has become one of the major public health concerns worldwide. According to the World Health Organization, one in eight people globally lives with obesity, and many more are overweight. High intake of sugary foods contributes to an unbalanced diet and increases the risk of developing diabetes, tooth decay, atherosclerosis, cardiovascular disease, and other non-communicable conditions.
As a rule, campaigns promoting healthy eating rely on the authority of experts such as physicians and nutritionists. Scientists set out to determine whether advice from ordinary people—friends and peers—could be just as effective. Researchers at the HSE Institute for Cognitive Neuroscience conducted an experiment involving 88 young adults who answered questions about their consumer behaviour. Participants were randomly assigned to three groups and exposed to different types of messages. The first group listened to a lecture by a nutrition expert on the risks of sugar consumption; the second heard a monologue by a university student presenting the same arguments; and the third listened to a discussion among three students expressing different viewpoints. Before and after the intervention, participants indicated—using an auction-based method—the maximum amount they were willing to pay for various products, including those high in sugar. This approach allowed the researchers to assess participants’ actual intentions rather than self-reported attitudes.

The results showed that all three types of interventions significantly reduced participants’ willingness to pay for sugary products. The key finding was that no statistically significant differences were found between the groups, indicating that peer recommendations were just as effective as expert advice.
Nina Arzumanyan
'In earlier studies, we demonstrated how expert persuasion can influence consumers' decision-making. In this study, for the first time, we show that adults are equally susceptible to both forms of influence—expert and peer endorsement. This may be because adults tend to be more autonomous from authority figures and are more strongly guided by the social norms of their referent group,' notes Nina Arzumanyan, Research Assistant at the International Laboratory of Social Neurobiology of the HSE Institute for Cognitive Neuroscience and first author of the study.
When communicating with peers, identification processes are activated, leading individuals to adopt others’ attitudes in order to maintain relationships within their referent group or because such behaviour aligns with their own value system.
Anna Shestakova
'Using peer persuasion may be a more accessible and scalable approach than relying on experts. People tend to trust those who are similar to them and share comparable life experiences,' comments Anna Shestakova, Director of the Centre for Cognition and Decision Making at the HSE Institute for Cognitive Neuroscience and co-author of the study.
In future work, the researchers plan to investigate the neurocognitive mechanisms underlying the influence of experts and peers on eating behaviour. This research will help clarify why different forms of social influence produce similar outcomes and how interventions aimed at promoting healthy eating habits can be made more effective.
See also:
HSE Economists Use Search Queries to Forecast Birth Rates
Researchers from the HSE Faculty of Economic Sciences have shown that the accuracy of birth rate forecasts for Russia can be improved by almost 50% by incorporating the dynamics of online search queries related to pregnancy and childbirth into forecasting models. In the best-performing models, the forecasting error fell from 4.6% to 3.2%. The findings have been published in Populations and Economics.
HSE Researchers Discover Who Eats Out in Russia—And Why
Around one-third of Russians (31.3%) rarely eat out or buy ready-made meals. The core group of active consumers—those who eat out or purchase prepared food almost every day or several times a week—accounts for only about 9% of the population. These are the findings of a study conducted by the HSE Institute for Social Policy. According to the researchers eating out is no longer a marker of high social status in Russia.
Ancient Craniiform Brachiopod: A Newly Discovered Species with a Unique Shell Shape and Lifestyle
Scientists from HSE University, MSU, and Tallinn University of Technology have studied a fossil species of ancient brachiopods that lived in a warm sea in what is now northern Estonia more than 445 million years ago. These ancient brachiopods developed a cup-shaped shell with a protective 'cap' that shielded them from overgrowth by other marine organisms. The study has been published in Palaeogeography, Palaeoclimatology, Palaeoecology.
Scientists Develop Bacterium-Sized Microlaser
An international team of researchers, including scientists from HSE University–St Petersburg, has developed microlasers that emit deep-ultraviolet light at a wavelength of 255 nanometres. The devices operate at room temperature, and the smallest of them measures just two micrometres in diameter—roughly the size of a bacterium. These microlasers could be used in sensors, spectroscopic systems, photonic chips, and communication devices. The paper has been published in Optics & Laser Technology.
HSE Develops App for Assessing Phonological Processing in Children
Researchers at the HSE Centre for Language and Brain have developed a new digital tool for assessing children's phonological processing skills—the ZARYA (Sound Analysis of the Russian Language) test battery. It is the first standardised application in Russia designed to provide a fast and reliable assessment of children's ability to distinguish speech sounds, retain them in working memory, and perform phonemic analysis. The app runs on Android tablets and smartphones and is available for download from RuStore. Details of the test validation have been published in the Journal of Speech, Language, and Hearing Research.
Researchers Discover How Spelling Errors Slow Down Reading in Russian
Psycholinguists from the Centre for Language and Brain at HSE University–St Petersburg have shown that words that are frequently misspelled are processed more slowly by readers, even when presented with the correct spelling. The researchers confirmed this effect for the first time using Russian-language materials and found that response speed is most strongly linked to how confidently individuals can distinguish the correct spelling of a word from an incorrect one. The study has been published in The Mental Lexicon.
Scientists Discover Why Europium 'Misbehaves'
Europium is a rare-earth metal responsible for the pure red glow in displays and other luminescent materials. For a long time, however, it refused to emit light when surrounded by certain organic molecules known as acylpyrazolone ligands. Chemists have now uncovered the reason: in europium complexes with these ligands, a 'black window' appears—a charge-transfer state in which the energy absorbed by the ligand is dissipated as heat rather than emitted as light. Understanding this mechanism opens the way to designing more efficient red-emitting materials for displays, fluorescent thermometers, and chemical sensors. The results have been published in Dalton Transactions.
HSE Economists Reveal How the Wage Gap Emerges Among Vocational School Graduates
HSE researchers examined the careers of 600,000 graduates of Russian secondary vocational education programmes and found that at the start of their careers, the gender wage gap reaches 23%, doubling after three years. This disparity is largely due to male and female students choosing different occupations when enrolling in vocational schools. These were the findings made by Sergey Roshchin, Natalya Yemelina, and Ksenia Rozhkova from of the HSE Faculty of Economic Sciences. The article has been published in Educational Studies.
HSE Researchers Make Aldehydes Perform Dual Function
Chemists from HSE University have discovered a way to carry out a reductive addition reaction without using an external reducing agent. Instead, the required 'resource' is supplied by the aldehyde itself, one of the reaction participants. This approach helps prevent unwanted side reactions, reduces toxicity, and simplifies the production and synthesis of organic molecules, including those used in the manufacture of medicines. The study has been published in Journal of Catalysis.
HSE Scientists Explain Why Findings in Autism Research Differ
Researchers from the Cognitive Health and Intelligence Centre at HSE University conducted the first-ever systematic review of studies on the specifics of emotion-from-motion perception in autism. The review showed that differences found between autistic and non-autistic individuals are largely associated with the experimental design and the types of tasks given to study participants. The review findings have been published in Research in Autism.


