I’m constantly contactable, I have no personal boundaries, and my attention span disappeared a long time ago. Since the first iPhone in 2007, smartphones have become indispensable to modern life, with the average person in the UK spending four hours and 20 minutes online per day. “Social media provides frictionless access to an infinite universe of mostly free digital drugs,” says Anna Lembke, author of Dopamine Nation. “And the algorithm tailors the experience for each unique brain, making it very reinforcing, while also injecting just enough novelty in the infinite scroll to overcome boredom and tolerance. All these features combined keep us clicking and swiping long after we want to.” Over time we develop tolerance, which means “we need more of it and a more potent form to get the same effect.”