12.The evidence we received during our inquiry detailed a wide range of possible effects, both positive and negative, that social media and screen-use may have on the physical and mental wellbeing of young people. A note of caution, however, was sounded by some witnesses about the reliability and validity of the evidence base. Before outlining the benefits and harms associated with young people using social media and screens, this Chapter considers the methodological and theoretical quality of the research conducted in this field, and its implications for policymaking.
13.Witnesses emphasised that ‘screen-use’ and ‘screen-time’ tended to be poorly defined, both in research studies and in the mainstream press, with limited effort being made to consider what the screen was being used for and the type of screen being used. The Science Media Centre, for example, noted that different types of technologies were simply “lumped together under the heading ‘screen time’”, to the extent that it had become shorthand for “many diverse things”. Similarly, Dr Peter Etchells, Senior Lecturer in Biological Psychology at Bath Spa University, highlighted how only a limited amount of research had attempted to differentiate between types of screen-time, thereby making it difficult to know if “an hour of watching an age-appropriate television is different to using social media for an hour, or playing a video game for an hour”.
14.We also heard that answering this type of question was further complicated by the often outdated nature of the screens considered in existing studies. As the Royal College of Paediatrics and Child Health (RCPCH) explained:
A major weakness in the current literature is its domination by television screen-time, which forms a rapidly decreasing proportion of children’s overall screen behaviour. Smaller numbers of studies have examined computer use or gaming, and very few studies have included mobile screen devices.
Consequently, in its review of ‘screen-time on health’, the RCPCH concluded that it was “unclear to what extent [existing] findings on screen-time can be generalised” to smart phones.
15.The methods used to quantify ‘screen-time’ were similarly highlighted as problematic. Dr David Ellis, Lecturer in Computational Social Science at Lancaster University, reported that “time spent in front of a screen [was] almost never measured directly” but instead was reliant on ‘self-reporting’. This, he suggested, was problematic for several reasons:
not least that people often have little conscious awareness of such automatic behaviours (e.g. smartphone checking). Indeed, our own research has demonstrated that people have little insight regarding how many times they check their smartphone each day. Measuring screen time directly, we observed that people were checking their smartphone 85 times a day on average.
16.In an open letter to The Guardian in 2017, an international group of scientists described the concept of screen-time as “simplistic and arguably meaningless”. Focusing on the amount of screen-use was similarly deemed “unhelpful”. What was missing from the evidence base, they argued, was an examination of the “context of screen use, and the content that children encounter when using digital technologies”, both of which may “have a much greater impact than sheer quantity alone”. Duncan Stephenson from the Royal Society for Public Health also emphasised that a more “nuanced picture” was needed and set out the difference between active participation and passive consumption of social media:
If you are using social media and are participating, that can be a positive, but smartphones are geared towards consuming information. There is some evidence that, if you are just consuming information, it impacts on levels of anxiety.
The RCPCH found it “concerning” that “so little research” had examined “the benefits and harms from social media and mobile phone screen use”, given that “it affects almost all young people”.
17.Across the written evidence, there was an acknowledgement that social media remains a relatively new phenomenon and, as such, there had been a limited amount of time during which to research and understand its impacts. The Education Policy Institute, for example, described the effects of social media as “a young research field”, with the Royal Society for Public Health, the Science Media Centre and techUK, each noting that, as a result, there was not yet a large, well-established body of research in this area.
18.In addition to concerns about the quantity of evidence available, witnesses questioned the quality of existing research studies that had examined the relationship between social media and the physical and mental health of young people. The majority of problems were linked to the design of the research. UK Research and Innovation (UKRI) called for more “carefully designed, multi-disciplinary studies”, noting that “robust answers to concerns” were most likely “to come from research studies that consider social media not in isolation but as part of the complex environment for young people”.
19.The need for research to focus more on the context in which social media use occurred was also emphasised by Dr Vicky Goodyear from the University of Birmingham. Dr Goodyear told us that her research showed that “school physical education, parents and other family members and peers played a key role in how much time [young people] spent on social media, but also what they were looking at and why”. She added that “evidence from broader samples of young people in different contexts and different demographics” was needed “to be able to understand what the influence is and define an effective response”.
20.A review undertaken by Unicef’s Office of Research similarly stressed that “children’s online experiences cannot be studied in isolation from their lives in general” and that “more control variables need to be included in quantitative studies to ensure that variables that have known effects on child well-being outcomes are not excluded”. These include factors like age, gender, personality, life situation, as well as their social and cultural environment. At present, there is thus a limited understanding of who is at risk and if some groups are potentially more vulnerable than others when online. This point is examined further in paragraph 54.
21.An additional limitation, linked to research design, concerned the reliance on studies that were “almost always correlational in nature” when examining the effects of social media. Professor Peter Fonagy, National Clinical Adviser on children and young people’s mental health at NHS England, explained that these studies encounter the “chicken and egg problem”; namely that it is difficult to “untangle causation” since it is not possible to determine whether a health effect is the cause or consequence of using social media. As Dr Mark Griffiths, Professor of Behavioural Addiction, from Nottingham Trent University told us:
What we have is a lot of what we call cross-sectional snapshot research, which is not longitudinal […] There is no good causal evidence. We have lots of correlational evidence. I would add that there have now been over 100 studies of Facebook addiction. Most of them have very poor-quality data. There are very few nationally representative samples. There is almost nothing in terms of longitudinal research.
22.According to CLOSER, “longitudinal research using existing studies” is needed in order “to track prevalence of social media and screen-use over time and uncover the long-term impacts on young people’s health”. Existing, longitudinal studies include the Millennium Cohort Study which follows the lives of a sample of over 18,000 babies born in the UK between 2000 and 2001, and Understanding Society—the UK Household Longitudinal Study—which covers 40,000 households and includes all ages (there is a special questionnaire for children aged 10–15 years). To move beyond correlational studies, Dr Heather Woods from the University of Glasgow also advocated for the use of wearable devices “to monitor in real time who is doing what and when and what they are looking at, as well as the nature of the social interaction”.
23.Where associations between social media and mental health had been found, some witnesses emphasised that the effects were “small”. According to Amy Orben, a lecturer in psychology at the University of Oxford:
Oftentimes, we do not find any effects. When we do find effects, they are extremely small. When we take the whole picture into account, they become vanishingly small. From the perspective that there has not been any really good quality evidence, I do not see that that link can be said to be present.
Christopher Ferguson, Professor of Psychology at Stetson University, Florida, put the problem slightly differently. He told us that the evidence linking social media to children’s mental health was “very poor” and that much of this was due to a:
failure to communicate the difference between “statistical significance” and “effect size” when discussing research in the social sciences. Put simply, particularly with large samples, it is possible for some studies to achieve “statistical significance” but report effects that are so small or trivial that they would have little actual impact on children in the real world.
24.Several witnesses emphasised that a lack of access to key data on social media was holding back the development of the evidence base. Professor Andrew Przybylski, Director of Research at the Oxford Internet Institute, explained that while social media companies “collect, store, and profit from extremely rich and sensitive data on our daily lives” and were potentially “indispensable partners for the large-scale transparent scientific investigations that will lead to actionable evidence-based policy insights” such partnerships were identified as the exception rather than the norm. Professor Przybylski described a “fundamental informational asymmetry between industry researchers and academic scientists”, while Dr Max Davie from the RCPCH expressed his frustration at companies like Facebook and Twitter who “have data”, but who were “not sharing it with researchers to look at the actual consequences, the patterns of use and the effect”. Building on Dr Davie’s point, Dr Heather Woods from the University of Glasgow agreed that it was “very difficult to access data […] the data are there, but enabling us to have access to it would give us a much more constructive answer to your question[s]”.
25.There are existing precedents for this type of data sharing with bona fide researchers. Dr Mark Griffiths from Nottingham Trent University noted that gambling operators had, voluntarily, made data about their users available to researchers. Dr Griffiths added that “social media companies have that data and, therefore, I think they should be regulated to use that data to help in those cases [where consumptive use leads to a potential problem]”. Academics were not the only witnesses to emphasise the need for greater access to social media companies’ high-level data on how their platforms are used: Ofcom also raised information and data gathering powers.
26.Regulated industries, such as energy and telecommunications, are required to share data with their relevant regulator about—among other things—customer service and harms. Since social media companies are not currently regulated in the same way as a utility company, they are under no such obligation to share this type of information. While Ofcom has a duty under section 11 of the Communications Act 2003 “to promote, and to carry out research in, media literacy”, which includes “electronic media” and “electronic communications networks”, Ofcom does not have the power to require online platforms to share high-level data with the regulator. Such data might include how long users are spending on a particular platform, or the age profile of users. Instead, this and other information is gathered by Ofcom through annual surveys with both adults and children.
27.Yih-Choung Teh, Group Director of Strategy and Research at Ofcom emphasised that “information-gathering powers” were something Ofcom “felt [were] quite important in [its] existing work, whether on broadcasting or telecoms”. Similarly, Sharon White, Chief Executive, Ofcom told the Digital, Culture, Media and Sport Committee in October 2018 that in order to “put sunshine on this area”, it was important to get access to the relevant data and information. Ms White added that, even in those instances where Ofcom did have “statutory information-gathering powers”, such as for telecommunications, it had taken “four or five years […] to get data that [it believed] is the right quality and the right consistency to put out to the public” on issues such as “customer service”.
28.Facebook emphasised that it did have “partnerships with academics, NGOs and experts to […] ensure that young people are kept safe online”. The company also recognised the “the need for more research” and explained that they had “committed to addressing […] and bridging some of the gaps that the research shows”.
29.In order to develop a more valid and reliable understanding of the relationship between the use of social media by young people, and its effects on their health, the information asymmetry between tech companies, the Government, other public bodies and bona fide researchers must be addressed swiftly.
30.Regardless of whether Ofcom’s remit is eventually expanded to cover social media platforms, its existing obligation to collect data on the ‘media literacy’ of both adults and children (as set out in the Communications Act 2003) should be strengthened through establishing statutory information-gathering powers. Such powers should require social media companies with registered UK users to provide the regulator with the high-level data it needs to fulfil its duties with respect to media literacy, with legislation introduced in the next Session.
31.While respecting data protection principles, social media companies should make anonymised high-level data available, for research purposes, to bona fide researchers so that a better understanding of social media’s effects on users can be established. The Government should consider what legislation needs to be in place to improve access by researchers to this type of data.
32.Across the written and oral evidence, both academics and non-governmental organisations highlighted the work of Professor Andrew Przybylski as the “best quality” research currently available on the effects of digital screen-time on the mental wellbeing of young people. Based on data provided by more than 120,000 British adolescents, Professor Przybylski and colleagues found that the relationship between screen-time and wellbeing was “most probably non-linear” and that “moderate engagement in digital activities has little detrimental effect on, and even some positive correlates with, well-being”.
33.The researchers suggested that it was “possible that digital technologies, when used in moderation, afford measurable advantages to adolescents” while also reporting that “high levels of engagement may have a measurable, albeit small, negative influence”. For the most part, however, Professor Przybylski agreed with other witnesses that the existing evidence base was “mixed and generally low in empirical quality”. The benefits and risks of social media and screen-use are examined in detail in Chapter 3.
34.The Government acknowledged that “there is a need for further evidence around the impact of social media and screen-use on children’s physical and mental well-being”. In October 2017, it published a Green Paper on its Internet Safety Strategy and held a public consultation on its proposals. Over 500 individuals and 62 organisations responded. A key theme from the consultation—highlighted in the Government Response to its Green Paper in May 2018—was the need to build a “more robust evidence base”, across a range of areas, to inform the Government’s work. In the context of mental health, for example, the Government stated that the “evidence around the impact of social media and internet use is not yet conclusive”.
35.The Government’s approach to date, however, has been to commission several evidence reviews, rather than undertake new research studies. DCMS, for example, was reported to be “carrying out a rapid evidence review on trolling”, while in 2017, the then Health Secretary, Rt Hon Jeremy Hunt MP, asked the Chief Medical Officer (CMO), Dame Sally Davies, to “lead a systematic review to examine all relevant international research” on the relationship between social media and the mental health of children and young people. The results of Dame Sally’s review had not been published at the time of writing. Additionally, the CMO’s 2013 annual report, Public Mental Health Priorities: Investing in the Evidence noted that while there were “widespread concerns” about the potential negative effects of electronic media, including “increased physiological arousal, decreased attention, hyperactivity, aggression, antisocial or fearful behaviour, social isolation and excessive use or ‘technological addiction’”, the evidence for those effects was found to be “sparse and contradictory”.
36.The only new, original research being sponsored by the Government was NHS Digital’s prevalence survey on children and young people’s mental health which, for the first time, covered social media use and experience. This was published in November 2018. Government departments do have research budgets, albeit of varying sizes. Following the Nurse Review of the UK Research Councils in 2015, which called on Government departments to have “a more strategic approach in relation to their departmental R&D programmes”, the majority of Government departments now issue documents setting out their “Areas of Research Interest” (ARI).
37.DCMS describes its ARI as setting out those “research questions that will help […] address the more immediate policy challenges facing the department” and “highlights areas where we [the department] encourage new research and discussion”. It does not, in other words, attach any funding calls to the research questions posed in the ARI. While the need for further research into “cyberbullying” and “sexting” among UK children is identified, there is nothing specifically in the ARI on the relationship between mental health and social media use, despite this being a “policy challenge” the department is currently facing. When asked in December 2018 whether ARI’s risked becoming ‘pie in the sky’ documents if they did not have funding attached to them, the Government Chief Scientific Adviser, Patrick Vallance, gave a measured response. He told us that if it transpired “that turning them [ARIs] into action is difficult because they do not have the funding in the first place, we will need to look at it”.
38.We commend the Government for its efforts to think more closely about online harms and how best to address them, particularly when those harms have serious, detrimental effects on the lives of young people. While the Government has undertaken a wide-ranging consultation process through the publication of its Internet Safety Strategy Green Paper, it is disappointing that it has not sought to address the current limitations of the evidence base by actively commissioning new research. As the Government Response to its Green Paper acknowledges, the evidence on the impact of social media on mental health “is not yet conclusive”. That the field requires more robust research should not come as a surprise when the Chief Medical Officer described the evidence base, in 2013, as “sparse and contradictory”.
39.To ensure that policy is evidence-based, and that the research needs of Government departments are met, departmental ‘Areas of Research Interest’ documents must be accompanied by periodic funding calls. Such calls need to take place ahead of an area becoming the subject of a major policy initiative.
40.The existing Areas of Research Interest documents produced by the Department of Digital, Culture, Media and Sport and by the Department of Health and Social Care, should be expanded to include how to measure and monitor the harms related to social media use. As a matter of urgency, DCMS should also commission research focused on identifying who is at risk of experiencing harm online, and why, and what the long-term consequences of that exposure are on the young person.
18 Science Media Centre ()
19 Dr Peter Etchells ()
20 Royal College of Paediatrics and Child Health (). See also Neza Stiglic and Russell M Viner BMJ Open (2019) doi: 10.1136/bmjopen-2018–023191
22 Dr David Ellis, Lancaster University (
23 , The Guardian, 6 January 2017
24 , The Guardian, 6 January 2017
26 Royal College of Paediatrics and Child Health ()
27 The major social media platforms have been operating for less than 15 years; Facebook was launched in 2004, followed by Twitter in 2006, Instagram in 2010, and Snapchat in 2011.
28 Education Policy Institute ()
29 Science Media Centre (); The Royal Society for Public Health (); techUK ()
30 UK Research and Innovation (). UKRI is a non-departmental public body whose purpose is to invest in, and facilitate, research and innovation activities across the United Kingdom.
32 Daniel Kardefelt-Winther, Innocenti Discussion Paper 2017–02, UNICEF Office of Research – Innocenti, Florence, p 8
33 Dr David Ellis, Lancaster University ()
34 [Professor Fonagy]
36 CLOSER, the home of longitudinal research (). CLOSER is a collaboration of leading social and biomedical longitudinal studies, the British Library and the UK Data Service, funded by the Economic and Social Research Council (ESRC) and Medical Research Council (MRC).
38 [Amy Orben]
39 Dr Christopher Ferguson ()
40 Professor Andrew Przybylski, Netta Weinstein and Amy Orben ()
41 Professor Andrew Przybylski ()
45 Communications Act 2003,
46 See, for example, Ofcom, , November 2017
48 Oral evidence taken before the Digital, Culture, Media and Sport Committee on 31 October 2018 , Q3785 [Sharon White]
49 Facebook ()
50 [Dr Davie]; Dr Peter Etchells (); Department for Digital, Culture, Media and Sport (); techUK ()
51 Professor Andrew Przybylski, Netta Weinstein and Amy Orben ()
52 Andrew K. Przybylski and Netta Weinstein, “Large-Scale Test of the Goldilocks Hypothesis: Quantifying the Relations Between Digital-Screen Use and the Mental Well-Being of Adolescents”, Psychological Science, Vol. 28 (2017) pp204–215
53 Andrew K. Przybylski and Netta Weinstein, “Large-Scale Test of the Goldilocks Hypothesis: Quantifying the Relations Between Digital-Screen Use and the Mental Well-Being of Adolescents”, Psychological Science, Vol. 28 (2017) pp 204–215
54 Professor Andrew Przybylski, Netta Weinstein and Amy Orben ()
55 Department for Digital, Culture, Media and Sport ()
56 HM Government, , May 2018, p 12
58 Annual Report of the Chief Medical Officer 2013 , Department of Health, September 2014, p101
59 Mental Health of Children and Young People in England, 2017 , NHS Digital, November 2018
60 Paul Nurse, , November 2015
62 Department for Digital, Culture, Media and Sport, , May 2018
63 Oral evidence take on Tuesday 11 December 2018, Q89 [Dr Patrick Vallance]
Published: 31 January 2019