Either overusing the internet destroys your brain, or it doesn’t. If it does then I apologize (I’m assuming that as you’re reading this humble blog instead of, say, Art Project, the Stanford Encyclopedia of Philosophy, or Celebrity Bitch Fest [Scarlett Johansson said WHAT?] then you probably are “overusing” the internet to some extent). If it doesn’t then I don’t (if you’re still with me (which you are (because of your perfect brain))).

Last week, several news outlets — the vast majority of which have websites that they openly encourage you to read — reported on new research suggesting that adolescents who spend lots of time on the internet show structural differences in their brains. Ergo: “Internet Addiction Changes Your Brain,” declared the Toronto Sun, “Addicted! Scientists show how internet dependency alters the brain,” warned The Independent, “Internet addiction can cause physical damage to the brain, just like drugs, say researchers,” said the Daily Mail, etc., etc., etc.

The study, published in the scientific journal PLoS ONE, compared 16 “healthy” adolescents with 17 adolescents with “Internet Addiction Disorder” (or IAD), and found differences in the structure of the white matter in their brains. Specifically, the IAD group had lower fractional anisotropy throughout their brains, which sounds pretty full-on. So it’s official. Overusing the internet causes kids’ brains to disappear. More or less.

Except of course…*drum roll*…no, it doesn’t. Not really. In fact, if anything, it’s the other way round. What’s of interest here is that, by and large, most media coverage has effectively reported this news in reverse, missing the point of the original research (but, admittedly, only by a few centuries). Here we have a plain old correlation-causation fallacy, one with dualistic —  or even religious — undertones.

Now, I bet you didn’t see that coming.

Most media accepted at face value the idea that genuine brain differences were found by the researchers. Now, as with all studies, we could (even as an intellectual exercise) choose to be skeptical of the findings. For example, we could quibble with the way the researchers diagnosed “internet addiction disorder” (they relied on self-reports). Or with the fact that we don’t know if the adolescents in either group had underlying health problems (which could would account for the differences in brains in ways unrelated to internet use). Or with the study’s pretty small sample size (which heightens the risk of fluke or erroneous findings).

However, even if we were to assume that the findings here are absolutely rock solid, we still have an important conceptual problem on our hands. And that problem is that a difference in brains between addicts and non-addicts is just not surprising. In fact it’s entirely to be expected. Actually, the study would have been more surprising if the researchers had failed to find differences in the brains of addicts and non-addicts.

This is because adolescents who have “internet addiction disorder” have psychological and behavioral characteristics that make them different to non-addicted teens. This much is obvious — it’s their psychological and behavioral characteristics that make these kids “addicts” in the first place. Now I’m not Descartes, but even I can surmise that differences in psychological and behavioral characteristics will be accompanied by differences in the brain. Hence, the correlation. So, if we find that addicts have different brains to non-addicts, why exactly is this a surprise?

And, surely the more likely direction of causality here is pretty straightforward? Namely, that differences in brain structure underlie (and precipitate) addictive behaviours, rather than the other way around?

Saying that “behaving in an erratically addictive way causes abnormalities in your brain” is a bit like saying “opening tin cans with your left hand causes left-handedness” or “bumping your head on door-frames causes you to be tall“.

And yet that’s exactly how much of the media interpreted the research. Here’s Fox News:

Internet addiction causes changes in the brain similar to that normally seen in people addicted to alcohol and drugs…The findings…revealed that the changes were similar to brain alterations observed in people addicted to alcohol and cocaine.

And here’s the Daily Mail:

Internet addiction disrupts nerve wiring in the brains of teenagers, a study has found – causing a level of brain damage normally seen in heavy substance abusers…Brain scans showed significant damage to white matter in the brain, proving, the researchers claim, that ‘behavioural’ addictions can cause physical brain damage in the same way as drug addictions.

Incidentally, the researchers did not “claim” that they were “proving” any such thing. What they in fact stated was:

There may exist partially overlapping mechanisms in IAD and substance use…this is not a controlled study of effects of internet use on brain structure…as a cross-sectional study, our results do not clearly demonstrate whether the psychological features preceded the development of IAD or were a consequence of the overuse of the Internet [emphases added]

In order to test the (Daily Mail’s) internet-causes-brain-damage theory, what is needed — at the very least — is a longitudinal study. In other words, what’s needed is a study where researchers catch people before they develop IAD and then test them over time to see if extreme internet use genuinely precedes any brain alterations. Of course such a research project would be extremely difficult to get right. For one thing, as the scientists could not possibly know in advance which members of the population will go on to develop IAD, they would likely end up with a huge amount of wasted data from participants who remained healthy, before striking it lucky by encountering a single genuine IAD case. They would then need to repeat this process of data wastage several times in order to accumulate a statistically worthwhile sample of IAD sufferers.

And what of those religious undertones I mentioned? Well, the temptation to choose the “IAD-causes-brain-changes” theory rather than the (more parsimonious) “brain-changes-cause-IAD” theory probably reveals a sentimental attachment to dualism. People prefer the idea that your thoughts, feelings, and actions affect your biology, rather than the idea that your thoughts, feelings, and actions are driven by biology.

For one thing, if your thoughts, feelings, and actions are driven by biology, then when you die — and when all those biological cells that make up your brain turn to dust — your capacity to “think”, “feel”, or “act” will surely disappear with them. A bit grim, eh? Well, throughout history, people have tended to find such ideas disturbing. And throughout history, people have tended to attach credence to worldviews that allow for a post-death existence; worldviews that accordingly downplay the impact of biology on behaviour, and which prefer instead the notion that biological stuff is always the consequence rather than the cause.

In other words, they prefer the the idea that your body — which clearly dies and decays into dust — is a wholly separate thing from your mind — which doesn’t die but lives forever in an afterworld. (So how come dowsing your brain with liquid alcohol causes your behaviour to change? And what about so-called “mind-altering” drugs that you campaign against? And how come people with brain injuries often suffer major cognitive deficits? Erm, stop asking questions…)

In the end, not liking something is insufficient grounds for not believing it. And, as a piece of cross-sectional research, the PLoS ONE study on IAD and brains is inherently inconclusive. Therefore, attempting to interpret its findings is more a matter of values than of science.

That said, personally I think it’s safe to surf away…

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