22 July 2025
Their work was recently published in The Lancet (Diabetes and Endocrinology), a leading journal in the field
In his work, the professor of Philanthropy and Sustainable Finance often sees that men overrate their own abilities. He observed this pattern before in investment behaviour, and now also in the way men deal with diabetes. Together with internists Nordin Hanssen and Max Nieuwdorp, he examined how men and women with type 1 diabetes perceive their glucose control – and how that perception compares to actual sensor data.
Smeets shares how the idea for this study came about: ‘Nordin and I often get together to talk about cutting-edge research in our fields. We met when we were PhD researchers at Maastricht University. We got to know each other through playing improvisation theater through the PhD Academy there. Almost twenty years later, we both live and work in Amsterdam at the University of Amsterdam. This gives us the chance to pursue research together. It's incredibly fun to work with people from a different discipline because you can learn so much, and combining insights from different fields can be quite powerful. During one of our regular meetings over a beer, we discussed a research idea from Coco Fuhri Snethlage, one of Nordin's PhD students. She wanted to study whether women with diabetes (Type 1) manage their disease differently than men. I already knew this from my finance research. Would we see something similar in the field of medicine? The answer turns out to be ‘yes’.’
Overconfidence may feel good, but it can lead to health risks when people underestimate their condition.Prof. Paul Smeets
So what did the data reveal? Both men and women spent about 60% of the time within a healthy blood sugar range. But men gave themselves a higher score than women did. They also reported fewer symptoms, even though the measurements didn’t support that. ‘Overconfidence may feel good,’ says Smeets, ‘but it can lead to health risks when people underestimate their condition.’
The research idea originated with PhD candidate Coco Fuhri Snethlage (Amsterdam UMC), and was made possible with funding from the Diabetes Fonds and the Dutch Diabetes Research Foundation (Stichting Diabetes Onderzoek Nederland).
For Smeets, this is a powerful example of how behavioural economics can offer insights far beyond the financial world. ‘By working with medical experts, you gain a much richer understanding of human behaviour – and that leads to surprising conclusions.’