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Chronotype, health and family: The role of biology, socio- and natural environment and their interaction

Periodic Reporting for period 1 - CHRONO (Chronotype, health and family: The role of biology, socio- and natural environment and their interaction)

Reporting period: 2019-11-01 to 2021-04-30

Problem being addressed. CHRONO examines the role of biology, differences in the social and natural environment and their interaction on understanding resilience to chronotype disruption and how these in turn impact health and family domains. Health outcomes include sleep, cancer, obesity and digestive problems with family research examining partnerships (sexual behaviour, union formation, dissolution, conflict), parent-child interaction and fertility.

What is it important for society? We all have a chronotype – known as an internal clock, circadian rhythm or ‘zeitgeber’ – which tells our bodies when to sleep, wake and eat and is affected by light cues. Recent changes such as increased light pollution (indoor, streets) and the widespread use of laptops and smartphones, places more individuals at risk of circadian disruption. Exposure to artificial light, particularly before bedtime, reduces sleep duration and quality. The rise of the 24-hour service economy and COVID-19 induced changes in working has likewise generated increased demands for night, shift and weekend work. In fact, 17% of employed Europeans regularly work evenings (6-10pm) and 6% night shifts (10pm-6am). Many now push their bodies against and beyond their clocks’ capabilities, with a staggering 25% reporting insomnia. Sleep deprivation is related to lower cognitive functioning, more accidents and increased interpersonal conflict, with chronotype disruption a ‘ticking time bomb of long-term health risks’. CHRONO has the potential to overturn long-held substantive findings and generate a unique new body of research. This includes for example challenging whether night shift work is causally carcinogenic or whether reported chronotype preference is simply an adaption to schedules rather than an intrinsic clock.

What are the overall objectives? The project has five main objectives: (1) develop a multifactor interdisciplinary theoretical model; (2) crowdsource a new sociogenomic dataset with novel precision measures and population diversity; (3) discover and validate innovative measures of chronotype; socio- (e.g. working time regulations) and geo-linked data (e.g. light); (4) ask new substantive questions to determine how chronotype disruption influences health and family outcomes and, via Biology x Environment (BxE) interaction, whether this is moderated by the natural or socio-environment; (5) develop new statistical models and methods to cope with contentious issues, address longitudinal questions and engage in novel natural experiments to transcend description to identify endogenous factors and causal mechanisms.
The pandemic caused considerable disruption but also opportunities for CHRONO. Given that the pandemic changed many working patterns and locations and timing, a fundamental research topic of CHRONO, we were ideally positioned as a new team to integrate COVID transformations of society, working and living into the project.

The research output of the project has exceeded our original goals during this first period, in spite of remote working and the pandemic. The output specified in the original grant was to produce one book and over 20-25 articles. The PI published one book in 2020 (MIT Press) outlining the analytical approach and methods and a review article in the Annual Review of Sociology setting out the theory, review and innovative directions moving forward.

For the first phase of this grant we have 13 peer reviewed articles in top journals including Nature Genetics, Nature Human Behaviour (x2), Proceedings of the National Academy of Sciences (x2), BMC Medicine, Annual Review of Sociology, European Sociological Review, Scientific Reports, Journal of Health and Social Behavior and Journal of Epidemiology and Community Health. Other projects we have under review or are working on are related to chronotype, working patterns and sleep using the innovative approaches. We were able to publish in highly respected peer-reviewed journals, but also across a wide variety of disciplinary journals. Some of the publications have had incredible scientific impact with one 2020 study in PNAS having already almost 600 citations and another 2020 study in Nature Human Behaviour with ~250.

In terms of dissemination and communication, particularly some of the COVID-19 work we pivoted to and linked to the CHRONO topics received considerable media attention and policy impact. The PI was invited as a national UK government advisor for behavioural insights related to COVID, to present to Parliamentarians in the UK, members of the US Secretary of State and appointed as one of 8 advisors to the European Commissioner for the Economy (Paolo Gentiloni) for post-COVID economic and social recovery. Her ECFIN advisory work is highly related to CHRONO, focussing on rapid changes in the ways of working and future employment during and after COVID. She was invited to present this work together with the Commissioner at the June 2021 Brussels Economic Forum. She also produced a report for the Chief Scientific Advisor of the UK about employment and health during and after COVID, used in UK policy development. In September 2021, she has been invited to present CHRONO work at the Royal Society of Canada as a keynote speaker at a Social Science and Genetics conference in the United States in October.
Our interdisciplinary work has pushed boundaries in this area of research by discovering the genetics of new types of behavioural outcomes and their interaction with the social and natural environment. We also discovered genetic overlaps between behavioural outcomes and interrogated correlation and causality in new ways that extend our understanding. In this next phase of the project, we will launch our innovative crowdsourced data collection project, which will host a wealth of data that allows us to examine our topics in new ways, using fundamentally new measures and work further on validating innovative measures and models.