Past English government campaigns have tried to curb youth drinking by focusing on the things young people might do while drunk and regret later: falling off scaffolding, vomiting or ending up looking a mess. And while more recent attempts, such as the Spread Campaign in Australia, have tended to be less overtly graphic, they still focus exclusively on harms associated with drinking, such as cancer. They use fear to try and scare people into changing their drinking behaviour. But despite their popularity with policymakers, psychological research has generally shown that campaigns based on fear do not change behaviour. What’s more, our research has found that even when young people thought they would regret what they did when drunk and made plans to drink less, they still ended up drinking the same amount. Over a number of research studies, we’ve tried to figure out why regret doesn’t change drinking behaviour. What we’ve found is that for many young people, the fear of missing out on the good things they might experience while drinking outweighs the fear that they might do something they regret. When young people in a focus group talked about their binge drinking, several downplayed the severity of the things they’d done while drunk – which included taking their clothes off in a nightclub and dancing naked on a table, and getting a tattoo of a footballer on their bum. They explained that the social benefits they got out of drinking, such as making shared memories, bonding and meeting new people, outweighed any negative consequences that followed. This helps to explain why health campaigns can be ineffective. If you can justify naked dancing or getting a tattoo on your bum, you’re not going be too bothered about feeling a bit sick the morning after. In a second, ongoing study, we talked to young adults about their fears of missing social events. Many told us that not attending these events meant exclusion from in-jokes based on shared experiences, leaving them feeling isolated. One of our interviewees even admitted an event would be “rubbish” but went anyway so as to not miss out. So, it seemed to us that regret might work differently for things you do – “action regret” – versus things you do not do: “inaction regret”. Applied to alcohol, this makes sense. Memories of hangovers fade, but you hold on to those shared experiences that mean so much. Conversely, not sharing experiences means you are left out of conversations, wondering what might have been. This means that Fomo – the fear of missing out – might be a better predictor of young adults’ drinking behaviour than anticipating regret. For our most recently published research study, we recruited over 100 young adults aged 18-30 and asked them to report the Fomo they felt and how much they planned to drink. They did this three times a day on three consecutive weekends. We also asked them how much they had gone on to drink each time. Measuring Fomo and drinking plans multiple times over a short period helped us understand fluctuations in feelings and drinking plans. Our results show that experiencing higher levels of Fomo increased how much young adults planned to drink, and led to them drinking more. This suggests one reason young adults drink more after experiencing Fomo is that they believe drinking more makes it more likely something memorable will happen. This supports what we found in our qualitative studies. In contrast, experiencing Fomo did not make young adults drink more frequently. In another study one of us (Richard) conducted, young adults’ drinking frequency was best predicted by social factors, such as how often young adults contacted their friends about drinking, and their drinking habits. As drinking often happens in social settings with friends, its frequency is likely to depend more on these social and contextual factors, rather than individual differences in Fomo or drinking plans. Overall, our research shows that Fomo – an entirely psychological phenomenon – influences young adults’ drinking plans and how much they drink. Such results can help explain why hard-hitting health campaigns that highlight regret following binge-drinking are ineffective at reducing binge-drinking. Young adults are more worried about missing out socially than about the hangover the next day.