Archives de catégorie : Psychologie/Psychology

Forget the stages of change in physical activity promotion

We recently shared a preprint presenting a very original investigation. During my Phd, I developed an interest for the Transtheoretical model to promote physical activity. If this model was over-studied in US or UK, the French sport psychology academic community did not explore it.

We (with @aj_romain) performed a cross-cultural validation of Processes of change questionnaire. We quantified the efficacy of Transtheoretical (TTM) based interventions in an awesome and collective project (d = 0.31, 95% CI [0.24, 0.37]). Then, we explored the moderator effects of TTM theoretical constructs in a meta-analysis and concluded that “no significant differences were found between personalized TTM-based interventions based on SOCs and non-personalized TTM based interventions”. However, TTM-based interventions implementing self-efficacy, decisional balance and processes of change constructs were more effective. Finally, we published a state of art about TTM and physical activity (Is there something beyond stages of change in the transtheoretical model?). We suggested that the processes of change should be targeted in priority for future TTM based intervention, and used to personalize a future interventions by targeting POCs with the lowest pre-intervention levels.

Consequently, J. Lapointe, (highly motivated) Msc student, developed a reproducible POC personalized TTM-based intervention. This intervention combined online training sessions and counseling. All details are available here. It was a terrific challenge because most of previous TTM-based interventions were not presented with a relevant level of details.

A set of single case experimental studies with a multiple baseline ABA’ design were carried-out. Physical activity was measured with a GENEactiv accelerometer and an agenda. Furthermore, TTM online questionnaires were weekly sent to participants (only for A-B phases).

As you can see below, we could visually examine the temporal patterns of TTM constructs before and during a behavior change intervention. We also performed piecewise linear models to analyze the intervention effects on physical activity behaviors (i.e., accelerometer and self-reported data). Findings were relatively different for each outcome. 6/7 participants increased their self-reported physical activity level. However, device measured PA of 5 participants was not significantly higher during B and A2 phases. Finally, a minimum of targeted 3/5 processes of change increased among all participants during our intervention. Don’t hesitate to comment this work. There are an important set of methodological weaknesses/ future challenge. 






  • Lapointe, J., Comtois AS, Romain, A. J., & Bernard, P. (2022). The Transtheoretical model’s processes of change in the heart of a physical activity intervention : A series of n-of-1. PsyArXiv.


Content of behavior change interventions for more sustainable diet behaviors.

The definition of sustainable diet varies between the authors and countries (1). However, the main characteristics are provided by Lonnie et al. (2) : to consume a variety of unprocessed or minimally processed foods, (i.e., whole-grains, pulses, fruits and vegetables), with moderate amounts of eggs, dairy, poultry and fish and modest amounts of ruminant meat . The Food and Agriculture Organization has published a more broad definition of sustainable diet: ‘Sustainable diets are protective and respectful of biodiversity and ecosystems, culturally acceptable, accessible, economically fair and affordable; nutritionally adequate, safe and healthy; while optimizing natural and human resources’ (3).

As you can imagine, it is particularly challenging to operationalize the sustainable diet behaviors for future interventions. A behavioral intervention could target the adopting plant-based diet, decrease the consumption of meats, sugar added product, ultra-processed food, soda, dairy products (particularly cheese)…. The behavioral change perspectives of sustainable diet are in line with debates about multiple health behavior change interventions (i.e., sequential versus simultaneous approach, number and order of targeted behaviors, rebound effects…) (4–6).

I tried to identify the systematic reviews examining the effects of ‘real-context’ behavioral interventions to help adults to adopt more sustainable diet behaviors. No surprise ! Most of published papers focused on animal-based diet or adoption of plant-based diets. It is easily understandable because the meat consumption reduction is particularly interesting in term of individual carbon footprint reduction (7,8) and is associated with various health benefits. Furthermore, the reduction of red and processed meat is also associated with a decrease of water and ecological individual footprints (9).

Five reviews and one report was found (10–15). I also added two narrative reviews of the special issue of Current Opinion in Behavioral Sciences about climate change (16,17). The number of interventions was relatively low and their respective efficacy is disputable. Most of interventions were performed in a ‘controllable’ context (e.g., cafeteria).

What are the psychological targets (and possible behavioral change techniques) to develop a future effective behavior change intervention ?

  • Health beliefs (to provide the information about health benefits or consequences) (10,11,14)
  • Food knowledge (to develop the skills and abilities preparation of new food or plant-based meals) (10,11,14)
  • Environmental beliefs (to provide the information about environmental benefits or consequences) (14,15)
  • Self-regulation (to facilitate action planning, to prompt self-recording) (11,14)

What are the most recurrent psychological barriers ?

  • Positive taste experiences with meat (10,12)
  • Health risks perception associated with a diet without meat (10,12)
  • Food preparation or purchase habits (10,10,13)
  • Poor social support or unwillingness of household members (10,13)

It is important to note that the findings are only generalizable in adults living in countries with high-incomes. Also, higher incomes and levels of education were associated with easier shift from meat- to plant-based diets (11,13).

The review about habit and climate change suggested that implementation intentions and gamification may be two effective technique to disrupt the meat consumption (17). Finally, the reported studies in review about the affects and emotions for climate change communication were mostly experimental. However, the authors suggested the ineffective role of threatening messages to modify the health behavior has not been verified for pro-environmental behaviors (16).

This article is a first attempt to identify the evidence based contents of future sustainable diet interventions. I recommend the well-designed protocol of Bianchi et al. , particularly their intervention logic model.

  • 1. Steenson S, Buttriss JL. The challenges of defining a healthy and ‘sustainable’ diet. Nutrition Bulletin. 2020;45(2):206–22.
  • 2. Lonnie M, Johnstone AM. The public health rationale for promoting plant protein as an important part of a sustainable and healthy diet. Nutrition Bulletin. 2020;45(3):281–93.
  • 3. Food Forum, Food and Nutrition Board, Health and Medicine Division, National Academies of Sciences, Engineering, and Medicine. Sustainable Diets, Food, and Nutrition: National Academies Press; 2018. Available from:
  • 4. Hyman DJ, Pavlik VN, Taylor WC, Goodrick GK, Moye L. Simultaneous vs Sequential Counseling for Multiple Behavior Change. Archives of Internal Medicine. 2007 Jun 11;167(11):1152.
  • 5. Sniehotta FF, Presseau J, Allan J, Araújo-Soares V. “You Can’t Always Get What You Want”: A Novel Research Paradigm to Explore the Relationship between Multiple Intentions and Behaviours. Applied Psychology: Health and Well-Being. 2016 Jul;8(2):258–75.
  • 6. Spring B, Moller AC, Coons MJ. Multiple health behaviours: overview and implications. Journal of Public Health. 2012 Mar 1;34(suppl 1):i3–10.
  • 7. Bernard P. Health psychology at the age of Anthropocene. Health Psychology and Behavioral Medicine. 2019 Jan 1;7(1):193–201.
  • 8. Ivanova D, Barrett J, Wiedenhofer D, Macura B, Callaghan M, Creutzig F. Quantifying the potential for climate change mitigation of consumption options. Environ Res Lett. 2020 Aug;15(9):093001.
  • 9. Fresán U, Marrin DL, Mejia MA, Sabaté J. Water Footprint of Meat Analogs: Selected Indicators According to Life Cycle Assessment. Water. 2019 Apr;11(4):728.
  • 10. Graça J, Godinho CA, Truninger M. Reducing meat consumption and following plant-based diets: Current evidence and future directions to inform integrated transitions. Trends in Food Science & Technology. 2019 Sep;91:380–90.
  • 11. Taufik D, Verain MCD, Bouwman EP, Reinders MJ. Determinants of real-life behavioural interventions to stimulate more plant-based and less animal-based diets: A systematic review. Trends in Food Science & Technology. 2019 Nov;93:281–303.
  • 12. Szejda K, Urbanovich T, Wilks M. An Evidence-Based Guide for Effective Practice. :111.
  • 13. Fehér A, Gazdecki M, Véha M, Szakály M, Szakály Z. A Comprehensive Review of the Benefits of and the Barriers to the Switch to a Plant-Based Diet. Sustainability. 2020 May 19;12(10):4136.
  • 14. Bianchi F, Dorsel C, Garnett E, Aveyard P, Jebb SA. Interventions targeting conscious determinants of human behaviour to reduce the demand for meat: a systematic review with qualitative comparative analysis. International Journal of Behavioral Nutrition and Physical Activity [Internet]. 2018 Dec [cited 2021 May 14];15(1).
  • 15. Abrahamse W. How to Effectively Encourage Sustainable Food Choices: A Mini-Review of Available Evidence. Frontiers in Psychology [Internet]. 2020 Nov 16 [cited 2021 May 14];11. Available from:
  • 16. Brosch T. Affect and emotions as drivers of climate change perception and action: a review. Current Opinion in Behavioral Sciences. 2021 Dec 1;42:15–21.
  • 17. Verplanken B, Whitmarsh L. Habit and climate change. Current Opinion in Behavioral Sciences. 2021 Dec;42:42–6.

What is the effectiveness of psychological interventions to reduce car using? 

A recent meta-analysis modeled the effects of psychological interventions (calledsoft interventions’) on car use (1). Most of included studies targeted the perceptions, beliefs, attitudes, values, and norms of participants. Three previous meta-analyses found a small effect size (h ranged from .12 to .16) or no effect on car use reduction (2).

The current meta-analysis included the published paper with a more robust method (i.e., experimental or quasi-experimental design), published in the past 30 years. The aims were to quantify the effect of psychological interventions and to identify the most important moderators. The following moderators were examined with uni-variate models : type of outcomes (e.g., number of trips versus traveled distance), type of intervention (e.g., information + free public transport ticket), psychological variable targeted (e.g., attitudes, habit, knowledge, self-efficacy, social norms), relocated participants, and study design. The authors also examined moderator effect of the percentage of women, incentives, city size by including the psychological variables targeted in models. 

No surprise ! 

Their meta-analysis was based on 41 interventions. They found significant and small effect size (g = 0.163, p < .001, 95% CI [0.11, 0.21]). The most interesting results were in the following findings.  As you can see, the most effective interventions targeted the social cultural and moral norms (g = 0.73), knowledge and awareness (g = 0.348) and those targeting capability and self-efficacy, (g = 0.12). 

The efficacy of interventions targeting relocated car users were not higher than other interventions. The other tested moderators (e.g., % of women) were not significant when the models were adjusted for psychological variables targeted in interventions. 

In conclusion, the decrease of car use after a psychological intervention, expressed in percentages, is approximately 7% ! In other words, the psychological interventions are not the panacea to decrease the car use. The ‘hard interventions’ are, for the moment, the most effective solutions (i.e., altering the physical environment (e.g., closing roads, building bicycle lanes, etc.) or legal or economic policies (e.g., prohibiting car traffic in city centers, congestion pricing, introducing parking fees).  

The future behavioral or psychological interventions should target the social and cultural norms in their interventions. Finally, I think that the academic psychology community should be humbler on this question (3).

  • 1. Semenescu A, Gavreliuc A, Sârbescu P. 30 Years of soft interventions to reduce car use – A systematic review and meta-analysis. Transportation Research Part D: Transport and Environment. 2020 Aug;85:102397.
  • 2. Arnott B, Rehackova L, Errington L, Sniehotta FF, Roberts J, Araujo-Soares V. Efficacy of behavioural interventions for transport behaviour change: systematic review, meta-analysis and intervention coding. International Journal of Behavioral Nutrition and Physical Activity [Internet]. 2014 Dec;11(1).
  • 3. Bernard P. Health psychology at the age of Anthropocene. Health Psychology and Behavioral Medicine. 2019 Jan 1;7(1):193–201. 

Comment tenter de modifier les comportements carbonés de nos collègues de travail ?

Des membres de l’association du Shift Project (Shift1team) ont réalisé un rapport pour guider les personnes qui souhaitent aider leur proche à modifier leurs comportements individuels carbonés. Celui-ci se présente sous la forme de 3 parties: un état des connaissances, un argumentaire sur les stratégies de changement de comportement et une série de cas concrets portant sur des comportement comme la réduction de consommation de viande ou le changement des modes de déplacement motorisés vers le transport en commun.

Vous trouverez ci-dessous une présentation qui en résume les points saillants. Les cas concrets sont très clairs et utiles pour faciliter la compréhension des aspects plus théoriques. Cependant, la section théorique, bien qu’elle se veut pluridisciplinaire dans le cadre des sciences humaines et sociales, est un peu trop centrée sur l’approche cognitive et ne fait pas état des données factuelles sur l’efficacité des techniques mises en avant (voir par exemple cet article sur le blogue).

Un des points les plus intéressants repose sur les tableaux ci-dessous. Les auteurs du rapport ont réalisé une évaluation des bénéfices ‘carbone’ et du niveau de difficulté d’une série de comportements carbonés. L’idée est très originale et permet de faire le tri des comportements que l’on souhaite cibler avec les meilleurs ratio carbone/difficulté.


Quelles stratégies pour favoriser l’utilisation d’une tasse réutilisable dans les cafés ?

Le nombre d’études qui porte sur cette question est relativement faible. Celles-ci sont en grand partie réalisées au sein de cafés universitaires.

Deux modèles semblent souvent mis en avant pour comprendre les déterminants de ces achats. Le modèle dualistique de la pensée (surtout sur les biais cognitifs), ainsi que des construits théoriques décrits dans le modèle COM-B de Michie (1) ou du modèle Transthéorique (2). Plusieurs études évaluent aussi des construits théoriques issus de la psychologie de l’environnement comme les croyances environnementales, l’investissement émotionnel et personnel face aux enjeux climatiques.

Si les stratégies de ‘manipulation douce’ (nudging) semblent avoir un effet sur certain comportement liés à l’environnement comme la réduction de consommation de viande (3), une seule étude a été identifiée sur la question des tasses réutilisables (4). Parmi ces stratégies, celles qui tentent de modifier la perception des normes sociales semblent les plus intéressantes (3). (voir exemple de l’usage des serviettes dans les hôtels). Cela prend généralement la forme d’une information décrivant le pourcentage de personnes effectuant le comportement souhaité, on appui ici sur la norme dite ‘descriptive’.

La difficulté ici, c’est qu’on souhaite modifier un comportement qui n’est pas encore entré dans la norme. C’est pour cela que les auteurs ont testé une formulation différente, dite de norme “dynamique” qui souligne que de plus en plus de personnes adoptent ce comportement ( “a growing number of people are changing their behavior”).

Ils ont examiné l’effet d’une affiche avec ce message disposé proche des 2 différentes piles de tasse. Ajouté à cela, il y avait un dépôt d’un euro pour l’utilisation d’une tasse réutilisable, et un coût additionnel de 0.10 centimes par tasse jetable. Après 10 semaines d’observation, l’augmentation de l’utilisation de tasses réutilisable étaient comprises entre 4.5 et 17.3%.

Une seconde étude a comparé 3 différentes interventions à un groupe contrôle afin d’identifier la ou les plus efficaces pour augmenter l’utilisation des tasses réutilisables (5).

  • Intervention centrée sur le valeurs environnementales – une courte vidéo issus d’un documentaire de la BBC , extrait portait sur les taux de tasses jetables non recyclées.
  • Intervention centrée sur l’intention – une tasse était offerte aux participants et on leur demandait à ce moment de rédiger un objectif d’utilisation pour les 6 prochaines semaines et de le laisser afficher chez eux et de le réviser si besoin
  • Intervention centrée sur le développement d’habitude – les participants choisissez la couleur de la tasse, puis ils leur étaient recommandé de toujours la déposer au même endroit chez eux après l’avoir lavée afin qu’ils puissent la voir avant de quitter leur logement et donc la prendre avec eux.
  • Les 156 participants renseignaient quotidiennement leur mode de consommation de café via une application durant 6 semaines.

A court terme, les participants des 3 groupes doublaient l’utilisation de leur tasse (sans différence d’effet entre les groupe) en comparaison au groupe contrôle. A 6 semaines, le groupe environnement semblait avoir un usage plus élevé que les autres groupes (5).

Une 3e étude impliquait 12 cafés proches d’universités afin qu’ils mettent en place les stratégies suivantes: affiches (voir plus bas), la vente ou la distribution gratuite de tasse réutilisable, un rabais pour ces utilisateurs, ou une ‘taxe’ pour les utilisateurs de tasses jetables (6). Il est important de noter que les cafés n’utilisaient pas toutes les stratégies. Globalement, la mise en place de stratégies était associée à une augmentation d’environ 4.3% (entre 3.3 et 7.6%) d’utilisation des tasses réutilisables. Les analyses statistiques suggèrent aussi que le rabais pour les tasses réutilisables n’avait pas d’effet en comparaison à la taxation des autres tasses (6).

Finalement, un rapport examine l’état de la littérature à propos des ‘taxes’ ou charges financières additionnelles qui pourraient entraîner un changement de comportement. Il semble que les petits charges des tasses jetables sont peu efficaces (0.05 – 0.10£). Une coût supplémentaire de 0.20 à 0.25£ (0.36 – 0.44 can$) entraînerait un changement de 49% des personnes sondées. Les auteurs ajoutent que cette stratégie semble être plus efficace dans les cafés locaux et non dans les chaînes. Il est important de souligner que le nombre d’étude est faible, que les résultats reposent majoritairement sur des sondages réalisés au Royaume uni.

  • 1. Allison AL, Lorencatto F, Michie S, Miodownik M. Influences on single-use and reusable cup use: a multidisciplinary mixed-methods approach to designing interventions reducing plastic waste [Internet]. 2020 Dec [cited 2021 Feb 24]. Available from:
  • 2. Lee J. A study for increasing reusable cup consumption in the coffee industry: focused on behavior change with motivation. Graduate Theses and Dissertations [Internet]. 2015 Jan 1; Available from:
  • 3. Nisa CF, Bélanger JJ, Schumpe BM, Faller DG. Meta-analysis of randomised controlled trials testing behavioural interventions to promote household action on climate change. Nature Communications [Internet]. 2019 Dec [cited 2020 Nov 24];10(1). Available from:
  • 4. Loschelder DD, Siepelmeyer H, Fischer D, Rubel JA. Dynamic norms drive sustainable consumption: Norm-based nudging helps café customers to avoid disposable to-go-cups. Journal of Economic Psychology. 2019 Dec;75:102146.
  • 5. Novoradovskaya E, Mullan B, Hasking P, Uren HV. My cup of tea: Behaviour change intervention to promote use of reusable hot drink cups. Journal of Cleaner Production. 2021 Feb;284:124675.
  • 6. Poortinga W, Whitaker L. Promoting the Use of Reusable Coffee Cups through Environmental Messaging, the Provision of Alternatives and Financial Incentives. Sustainability. 2018 Mar 19;10(3):873.