How to calm down an overstimulated brain

Helen Coffey, The Independent

If you’ve ever tried to go on a calorie-controlled diet or do a “digital detox”, you’ll likely have experienced the high-stakes battle between willpower and temptation. This capitulation to our base impulses is often framed, in mainstream culture, as weakness. We should be able to exercise enough self-control to put our phones aside or turn down the offer of a free cookie with our morning coffee. But what if our inability to stop doing things that are bad for us wasn’t really our fault at all? What if our core biological instincts were being manipulated?

That’s the conclusion that Nicklas Brendborg, a Danish biotech researcher, has come to. His upcoming book, Super Stimulated, explores the power of what have been dubbed “supernormal stimuli” or “superstimuli”. These are, in short, exaggerations of what an animal is naturally attracted to: “a stimulus that is a bigger, brighter or stronger version than the naturally occurring option”.

The term was first coined by a Dutch scientist, Nikolaas Tinbergen, after he ran a set of experiments with birds. He found that when he added fake eggs into the cage that were painted in bright colours and exaggerated to ridiculous proportions, the birds would inevitably choose to sit on the ersatz ones rather than their own eggs. The reason for this is not that the birds were stupid or fickle; it is because this impulse is biologically baked in. “They’ve evolved to have an instinct that says, the bigger and brighter the egg, the better,” says Brendborg, “because the healthier the female is, and the more food she has access to, the bigger and more colourful the egg tends to be.”

In nature, there’s a very clear biological limit to this: a bird can’t lay an egg bigger than itself, and it can only be so bright based on natural pigmentation. And so the bird has never needed to develop a “ceiling” to this inclination – which means we can “trick this bird to make the wrong choice”, says Brendborg.

Why is he telling me about birds? Well, because the same biological hijacking that was used on our fine feathered friends can — and is — being applied to us. The simplest direct comparison with the original experiment is sweets. “Take strawberries and strawberry-flavoured candy,” says Brendborg. “This is the exact same thing we’ve done — we’ve looked at the strawberries and said, ‘What is the essence of why these taste good?’ And one key reason is that humans like stuff that tastes sweet.” We evolved this preference over millions of years, because it was useful for finding valuable foodstuffs: if something was sweet in nature, that indicated the fruit was ripe and, crucially, not poisonous. We developed no “ceiling” in our desire for sweet food, because we never needed to; there’s a natural limit to how sweet (and calorific) naturally occurring foods can be.

But cut to modern times and modern technology, and it’s a real problem. We can now use refined and processed sugar to create strawberry sweets that are 10 times sweeter than a wild strawberry could ever be. Most people would, given the choice, probably prefer the strawberry sweet to the fruit. “And that starts a very unhealthy cycle where we end up making all the wrong choices for our health and wellbeing,” explains Brendborg.

We see this across the contemporary food landscape. Even savoury ultra-processed foods are packed with added sugar, because our stomach registers it (even if our tastebuds don’t) and cries out for more. Not to mention the amount of added salt and saturated fat present in much of modern food — both of which we’ve evolved to have a taste for. Our food is, quite simply, designed to make us overeat, as evidenced by an ever-worsening obesity crisis, with two-thirds of all British adults registering as overweight.

The problem doesn’t stop with food. Other superstimuli include; drugs, which crank up the dopamine and act as a shortcut to a temporary state of euphoria; and, of course, screens and smartphones, especially with the recent onslaught of news headlines sending us all into a headspin.

Again, biological imperatives are being manipulated. It’s no accident that phone apps feature bright colours. In nature, this often relates to ripe berries that are good to eat — hence our attraction to a pop of colour.