If behavioural science was a TikTok trend, would Gen Z listen?

Industry Insights


Dr Laura Meade


Using behavioural science to target vaccination hesitancy in our world’s largest demographic.


Immunization week

This week, the U.S. Centers for Disease Control and Prevention (CDC) and global public health partners recognize World Immunization Week. This year’s theme, #VaccinesWork for All, highlights the importance of vaccines to protect people throughout the lifespan and what we can do as a society to pursue this goal.1 However, as the world continues to ramp up COVID-19 vaccination efforts, stats about vaccine hesitancy raise some immediate challenges to this goal.


Gen Z

Gen Z are those born between 1997* and 2009. A generation that has grown up amid the burden of climate change, political insecurity and now the COVID-19 pandemic.  Prior to the pandemic they were set to enter a strong economy with record low unemployment.2 The pandemic has rocked this stability and changed the social, political and economic landscape, leaving a generation who may have the largest impact on future decisions uncertain about their future.  21% of Gen Z respondents in a US survey said they would not get vaccinated against COVID-19, while a further 34% would “wait and see” before getting vaccinated,3 a worrying yet insightful statistic. And we are not doing a good job at speaking their language to understand and address their concerns.


A shift in how knowledge is consumed

Social Cognitive Theory (SCT), which dates back to the 1970s, theorizes that knowledge is gained by observing others through interactions, experiences and influences.4 Gen Z is the first generation to grow up with the internet and social media, thus influencing how their knowledge is consumed. In 2018, 36% of Americans aged 18-29 reported that their main source of news was via social media.5 TikTok is a popular social media platform used by this population. It allows users to share their knowledge, skills and creativity through short videos. However, it has also created the opportunity for some users to spread misinformation to a captive audience. This has had far reaching consequences during the pandemic, leading people to question the safety and long-term effects of the vaccine. Consequently, the need to close the recognized communication gap between scientists and the general public6  has been brought to the forefront.


Using behavioural science to speak Gen Z’s language

Interventions to target behaviour change are most effective when they are tailored to the context and culture of the target population.7 Social media not only plays a key role in how Gen Z consumes knowledge, but in how they shape their identities and express their ideas. 8 Leveraging these platforms may allow for targeted interventions that speak their language. Co-designing interventions with the target population allows their voice to be heard and ensures the intervention is relevant and accessible. Collaborating with Gen Z influencers may help us understand the reasoning behind their hesitancy and how to address their concerns in a medium that speaks to them. This would allow us to align behavioural strategies most appropriately.


Behaviour change techniques

Behaviour change techniques (BCTs) are evidence-based strategies that facilitate behaviour change.9 These can be selected to address the needs of the population of interest. Some of these techniques lend themselves well to supporting behaviour change via social media platforms such as Instagram and TikTok.


Behavior change technique Description
Informed messages by credible sources

Short, insightful and entertaining communication by someone credible and respected.

Some scientists/practitioners with great social media presence that we suggest:




Information about social and environmental consequences Appeal to this age group’s interest in the greater good by providing information and feedback about the consequences of not receiving a vaccine.
Tailoring Recognize and address the concerns and barriers specific to Gen Z and their reasons for hesitancy. Address these concerns and be honest about information gaps.
Social comparison Build social norms by identifying others (who are relatable) who have received their vaccine or plan to do so.
Remove aversive stimulus Currently, additional information about COVID-19 requires users to click on an informational toolbar on Instagram or TikTok, diverting the user. Users will be less likely to engage with this content if it has a negative consequence (ie., they can no longer watch the video).  Make information accessible and immediate, without extra work required by the user.
Normalisation Understand that there are many emotions involved and that it is normal to feel unsure, but to direct people to evidence-based knowledge and facts to ease uncertainty.
Identity associated with behaviour change Align behaviours associated with vaccine uptake with those that speak to this generation. Harness the creative opportunities provided by social media platforms to support the creation of new identities as someone who uses scientific evidence to make informed decisions.



*There are some conflicting viewpoints as to when this generation starts.  We have used the definition set by the Pew Research Centre.

Picture: Designed by Freepik


  1. Centres for Disease Control and Prevention. World Immunization Week. Accessed at https://www.cdc.gov/globalhealth/immunization/wiw/index.html on 15 April, 2021.
  2. Pew Research Centre. On the cusp of adulthood and facing an uncertain future: what we know about Gen Z so far. Accessed at https://www.pewresearch.org/social-trends/2020/05/14/on-the-cusp-of-adulthood-and-facing-an-uncertain-future-what-we-know-about-gen-z-so-far-2/ on 15 April, 2021.
  3. The Harris Poll. The Insight. Accessed at http://theharrispoll-8654532.hs-sites.com/the-insight-wave-59?__hstc=78454539.ee3724b127e8805c2689745e79e84983.1618428882837.1618428882837.1618428882837.1&__hssc=78454539.4.1618428882838&__hsfp=1008882404 on 16 April, 2021.
  4. Luszczynska,A., & Schwarzer,R. Social Cognitive Theory. Predicting Health Behaviour, Connor, M., & Norman,P, Open University Press, 2005, (pp 127-170).
  5. Pew Research Centre. Social media outpaces print newspapers in the U.S. as a news source Accessed at https://www.pewresearch.org/fact-tank/2018/12/10/social-media-outpaces-print-newspapers-in-the-u-s-as-a-news-source/ on 16th April, 2021.
  6. Hunter P. The communications gap between scientists and public: More scientists and their institutions feel a need to communicate the results and nature of research with the public. EMBO Rep. 2016;17(11):1513-1515. doi:10.15252/embr.201643379
  7. Shahsavari H, Matourypour P, Ghiyasvandian S, Nejad MRG. Medical Research Council framework for development and evaluation of complex interventions: A comprehensive guidance. J Educ Health Promot. 2020 Apr 28;9:88. doi:10.4103/jehp.jehp_649_19
  8. Monahan, S., & Secaf, S. Sponsored by Yone, 2017.
  9. Michie S, Richardson M, Johnston M, Abraham C, Francis J, Hardeman W, Eccles MP, Cane J, Wood CE. The behavior change technique taxonomy (v1) of 93 hierarchically clustered techniques: building an international consensus for the reporting of behavior change interventions. Ann Behav Med. 2013 Aug;46(1):81-95. doi: 10.1007/s12160-013-9486-6.