A new study from researchers at the University of Oxford has tracked data from several hundred thousand subjects finding digital technology use accounts for less than half a percent of a young person's negative mental health. The research suggests everything from wearing glasses to not getting enough sleep have bigger negative effects on adolescent well-being than digital screen use.

The effects of digital screen time on children's well-being and development is a source of huge debate at the moment. While concerns over the effects of these new devices on childhood development are not unwarranted, scientists have not been able to reach a clear consensus on the topic.

The latest study is one of the largest and most definitive to date, examining data from over 350,000 subjects in the UK and US. The first challenge the researchers faced with this study was trying to overcome the selection bias that can plague this type of technology research.

"Of the three datasets we analyzed for this study, we found over 600 million possible ways to analyze the data," explains Amy Orban, an author on the new research. "We calculated a large sample of these and found that – if you wanted – you could come up with a large range of positive or negative associations between technology and wellbeing, or no effect at all."

The new study used a method called Specification Curve Analysis (SCA) to dig through the data and find meaningful associations. The method essentially attempts to analyze the data using as many justifiable specifications as possible. After calculating as many variables as the data would allow the researchers are then able to compare the effects of digital technology use on well-being against a vast array of other factors.

The results were stark and convincing with digital technology use accounting for just 0.4 percent of a young person's overall negative well-being. Binge-drinking and marijuana use were noted as having significantly larger negative effects on a young person's well being. Bullying, for example, was found to have four times larger the negative effect on well-being than digital screen use.

On the positive end of the spectrum, things like eating a good breakfast and getting enough sleep were much more statistically relevant in affecting well-being than the effects of technology use.

"Our findings demonstrate that screen use itself has at most a tiny association with youth mental health," says Andrew Przybylski, lead researcher on the study. "The 0.4% contribution of screen use on young people's mental health needs to be put in context for parents and policymakers. Within the same dataset, we were able to demonstrate that including potatoes in your diet showed a similar association with adolescent wellbeing. Wearing corrective lenses had an even worse association."

Although this study is relatively robust it isn't without limitations, perhaps the most significant of these being how all digital technology use is rolled into one homogenous entity. Ben Carter, a researcher from King's College London who did not work on this new study, suggests the lack of specificity surrounding digital technology use is important when trying to interpret what this research means moving forward.

"This study was only able to look at the duration of use and not the way in which the technology was being used (the content and time it was being used) which could possibly provide a better indicator of well-being," says Carter. "For example, is the technology use of a twelve-year-old spending a few hours on a computer doing school work during the day the same as if it was say, 10pm at night and scrolling through social media posts for the same length of time? Therefore, the way in which technology is used by young people and the impact of social media specifically is something we need to look at in future studies."

Przybylski would perhaps be the first to agree with Carter's suggestion that more granular research is needed to ascertain specific and contextual consequences of digital technology use. Last year Przybylski published a study suggesting general digital screen time does not disrupt children's sleep. At the time Przybylski said, "Focusing on bedtime routines and regular patterns of sleep, such as consistent wake-up times, are much more effective strategies for helping young people sleep than thinking screens themselves play a significant role."

The general implication here is that screen time, in and of itself, is not a harmful causal agent. Max Davie, from the Royal College of Pediatrics and Child Health (RCPCH) in the UK, recently published new screen time guidelines suggesting general age-appropriate time limits for children are nearly impossible to quantify. The new RCPCH guidelines instead focus on positive activities such as socializing, exercise and sleep, noting that it is only when screen time displaces these activities that there is a risk to a child's well-being.

"This study supports the findings of our recent review of the evidence base on screen time, that while there are some negative associations between screen time and poor mental health, we cannot be sure that these links are causal, or if other factors are causing both negative health outcomes and higher screen time," says Davie.

Przybylski's research is working hard to overcome the big problem facing this kind of observational research into the effects of technology. It's a classic causation versus correlation dilemma, and in the field of technology research, individual bias cannot help but seep in. Kevin McConway, a professor in applied statistics from Open University, suggests the vast majority of modern screen time research suffers from this shortcoming.

"So if young people who report more screen use are also more likely to be depressed, that could be because screen use tends to cause depression, or it could be because young people who are depressed anyway tend to spend more time using screens," says McConway.

McConway's solution backs up the recommendations from Davie and the RCPCH affirming the best guidance is towards better general parenting principles rather than trying to determine an ideal hour-per-day amount of screen time that is appropriate for all children.

"The nuanced picture provided by these results is in line with previous psychological and epidemiological research suggesting that the associations between digital screen-time and child outcomes are not as simple as many might think," Przybylski and his team conclude in the recently published study.

It is becoming increasingly clear that there is no simple answer to the screen time debate. Not all screen time is created equal and parents looking for a straightforward answer regarding how much time they should allow their child to have with screens may begin to realize they are asking the wrong question.

The new study was published in the journal Nature Human Behavior.