Can a kind word change your life? I know from experience that it can. More than three decades ago, during the summer vacation at the end of my first year at university, I received a handwritten letter from my economics tutor, the effervescent and much-missed Peter Sinclair.
I’d been planning all along to drop economics in favour of other subjects, but Peter congratulated me on my end-of-year exam results, emphasised that those results were stronger than I might realise, and encouraged me to keep going. I decided to stick with economics after all.
I hope I can be forgiven my double take when I stumbled upon a recent working paper published by two academic economists, Olivia Edwards and Jonathan Meer. Their research answers a simple question: what happens if you do exactly what Peter Sinclair did for me, but on a much larger scale?
Edwards and Meer are at Texas A&M University, which has a large online introductory course in economics. Thousands of students enrol in the class — it is compulsory for many — and most of them are not planning to major in economics.
Since 2017, one of the instructors in the Texas A&M economics programme has emailed the best-performing students — roughly the top 10 per cent of the class. These emails praised their achievement, referred to them as top performers, noted that they had an aptitude for economics and encouraged them to sign up for further classes. Edwards and Meer were rerunning my own experience, but with hundreds of students each year.
The results were not trivial. Students just above the cut-off for receiving the email were about 40 per cent more likely to enrol in the follow-up intermediate microeconomics course — the chance of doing so rose from just over 20 per cent to just under 30 per cent. It’s remarkable to see such a trivial action — a nice email — having such a transformative effect, even if that transformation lasted only one semester.
Should we believe this result? There is a long and not wholly encouraging tradition in the social sciences of finding minor-seeming interventions that are supposed to unlock life-changing benefits. Many have later proved overblown or illusory.
The most notorious may be “power posing”, touted by one of its discoverers, psychologist Amy Cuddy, as “a free no-tech life hack”. This is the idea that taking a couple of minutes to adopt an expansive pose can boost your confidence and your performance in a job interview. This was a hugely influential idea in the world of business, but many psychologists now doubt the effect. Cuddy’s original co-author, Dana Carney, says “I do not believe that ‘power pose’ effects are real”, and that further research on the subject is a waste of time.
Another fashionable idea to emerge from psychology is that of the “growth mindset”. This idea starts with an obvious truth, which is that people get better with practice. From that truth comes a suggestion: maybe we should encourage children to think about skills they can develop, rather than treat them as people who either have talent or don’t. Mindless praise — “You’re so clever!” — might induce them to avoid difficult tasks, which might reveal they are not so clever after all. Instead, encourage children to work hard and reflect on how they might improve.
That’s all reasonable enough, but the growth mindset is easy to oversimplify and easy to oversell. Breathless claims have been made about how encouraging the right mindset can transform children’s prospects, but when the UK’s Education Endowment Foundation funded a rigorous trial of the approach a few years ago, it found disappointing results. The trial trained teachers in the approach and then gave schoolchildren two hours a week of mindset workshops for eight weeks. This admirable-sounding programme made no detectable difference.
So if weeks of mindset classes seem to make no difference, why should we believe that the encouraging email was so decisive in encouraging so many students to stick with economics?
It’s worth considering another successful intervention, one I described not long ago in this column. Researchers at BIT, the former “nudge unit”, have run large randomised trials revealing that patients are 25 per cent less likely to miss NHS appointments if they receive a text message pointing out how much it might cost the health service if they don’t show up.
Like the encouraging emails, these text messages are a tiny intervention that makes a substantial difference. Why? It may be because the text messages share another quality with the emails: they are well timed, well aimed, and informative.
The aim matters. The emails weren’t sent to everyone in the introductory economics class, but just the top 10 per cent. The text messages weren’t blasted out to every patient in the NHS database, but only to those with appointments. In a world full of generic messages, there is a power in being specific.
Providing information might matter, too. At least a quarter of the economics class at Texas A&M were awarded A grades, so the students receiving the email were being told something they probably did not know: that they were among the best of those A students. The BIT research on NHS text messages found that they were much more effective when they told people how much a missed appointment cost — a surprisingly high figure of £160.
Timing might be the most important difference of all. The text message reminders didn’t need to change anyone’s personality or habits. They just needed to change one imminent act. Similarly, the emails encouraged pupils to sign up for one more class, not to reimagine their life goals.
The most famous and most effective “nudges” remain those that have focused on getting people to sign up for pensions.
Several different tactics have proved effective, but a key to their success is that unlike quitting smoking or going to the gym — or adopting a growth mindset — you may only need to sign up for a pension once.
By all means say kind things to everyone you meet. It will make life more pleasant for all concerned. But when those kind words also contain some insight and are spoken to the right person at the right moment, that is when the magic happens.
Written for and first published in the Financial Times on 24 July 2025.
Loyal readers might enjoy the book that started it all, The Undercover Economist.
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