Earlier this week, in questioning the significance of a "scientists find internet-addiction gene" story, I conceded that the scientific study in question did find something interesting: A gene that seems to be (very modestly) correlated with internet addiction also plays a role in nicotine addiction.
No. Whether heavy internet use deserves to be called an addiction or just a hard-to-break habit is a question about a behavior pattern and its attendant psychological states. To answer it we ask such things as how strong the cravings for the internet are, what lengths a person will go to in order to satisfy them, and so on. But even if we decide, after answering such questions, that a given person's internet dependence amounts only to a habit, and doesn't warrant the "addiction" label, it still makes sense that genes which mediate chemical addictions--nicotine, cocaine, whatever--would be involved.
To see what I mean by this is to see that, yes, a susceptibility to internet addiction (or heavy internet habituation, or whatever you want to call it) is "in the genes" -- but it's in lots and lots of genes, and it's in the genes of all of us.
The reason for this, naturally enough, lies in the process that created our species. Human beings are biochemical machines "designed" by natural selection to, among other things, form habits. In particular, we're designed to form habits that helped our ancestors survive and get genes into the next generation -- such habits as eating meat or fruit or having sex with auspicious mates or impressing people or even gathering tactically useful information about people (i.e., gossip). The habit-forming machinery involves the release of reward chemicals, such as dopamine, that make us feel good upon attaining these goals--upon eating fatty food, sweet food, having sex, hearing people laugh at our jokes or marvel at our exploits, hearing good gossip, etc.
Now, the environment that natural selection designed us for -- a hunter-gatherer environment -- didn't feature endless and readily available supplies of tasty food, and it didn't present constant and easy chances to mate or impress peers or pick up good gossip. Our ancestors had to spot their opportunities and then do some work to get these things--and only then, upon achieving these goals, would they get the chemical rewards that would bring pleasure and thus encourage them to repeat this work in the future. So it took some effort to reach that magic moment when, with your goal attained, chemically mediated gratification would ensue.
In the modern world, there are shortcuts to getting these rewards: Just ingest chemicals -- nicotine, cocaine, heroin, whatever -- that intervene directly in the chemical reward system, sometimes by mimicking neurotransmitters. For example: acetylcholine is a neurotransmitter that, when it binds to a neuron, can have various gratifying effects, including the release of dopamine. And nicotine can bind to certain kinds of neuronal acetylcholine receptors and elicit some effects that acetylcholine would bring. And there's some evidence (though here I'm approaching the limits of my comprehension of the science) that people with a particular variant of a gene involved in building acetylcholine receptors are more susceptible to nicotine addiction than other people.
Anyway, the main point is this: the biochemical mechanisms (including genes) involved in chemical addictions will naturally be the mechanisms involved in habit formation more generally since habit formation is what they were originally designed for. So when this German scientist announced triumphantly that a gene which seems to have a modest correlation with heavy internet use is a gene that may play a role in nicotine addiction he had told us (1) nothing that should surprise anyone; and (2) nothing that settles the question of whether this heavy internet use deserves to be called an "addiction" or merely a "habit." Either way, whether it's a habit or an addiction, it is going to involve pleasure-dispensing biochemical mechanisms of the sort that can get us addicted to such chemicals as nicotine and cocaine--because, again, it is through such pleasure-dispensing mechanisms that habits in general form.
All of this helps explain why internet use can arguably become addictive in the sense that some chemicals are addictive -- that is, we can develop a dysfunctionally strong devotion to the internet, a devotion that leads us to neglect obligations and responsibilities (such as getting a novel written). After all, the internet, like these chemicals, allows us to trigger our neuronal reward mechanisms with much less work, and much more frequently, than was possible in the environment of our evolution.
For example: In that environment, there was no pornography, much less the vast and instantly accessible supply found on the web. Nor was there the nearly infinite supply of gossip that is available now that we can spend our time trolling Facebook or living vicariously among celebrities and following their lives on TMZ. Nor was a robust round of social esteem always, potentially, just a moment away; it wasn't possible, in a very small and technologically primitive social universe, to at any time of day launch an observation or joke and hope for the prompt affirmation of dozens of retweets or Facebook likes. Nor was there a YouTube that permitted the easy indulgence of various natural human visual appetites -- watching endearing infants or two guys fighting or real-life slapstick or whatever.
In other words: the internet, like a pack of cigarettes or lots of cocaine, lets you just sit in a room and repeatedly trigger reward chemicals that, back in the environment of our evolution, you could trigger only with more work and only less frequently. That's why an internet habit, like a cocaine habit, can reach dysfunctional levels.
The above-listed forms of internet dependence -- porn, Facebook, TMZ, Twitter, YouTube -- are just a few of the possible ingredients of any one case of internet "addiction." And each of these ingredients itself involves God-knows-which neurotransmitters and neuronal receptors and, by extension, God-knows-how-many genes. And all of us have lots and lots of these genes--genes that make us susceptible to internet addiction. Because what the internet does is take lots of things that natural selection designed us to find gratifying and make them much easier to get.
Sure, some of these genes may vary from person to person in ways that make some people particularly susceptible to internet addiction (though environmental influences -- e.g. learning self-discipline -- presumably play a very big role). In fact, it will probably turn out that lots of genes vary in this way -- genes that influence impulsiveness or self-discipline generally, or genes that influence the strength of particular drives, like lust or the urge to gossip. In fact, there will turn out to be so many genes which are so modestly correlated with internet addiction that if journalists write stories every time such a gene is found, or is thought to have been found, they will find that they're not shedding much actual light on the situation.
And if they call these genes "internet addiction genes," that will be kind of misleading (which is why I've put that phrase in quotes in the title of this post). These genes are really just genes for being human. That's why using the internet well is a challenge for us all.