The team then carried out two online experiments, with data from 2,565 American participants in one and 4,046 in the other, in an attempt to ensure the findings were not simply down to, for example, a scenario in which people living with depression might find themselves with large amounts of free time.
In both experiments, participants were asked to imagine a defined amount of free time a day and what they would do with it, with one experiment looking specifically at whether it was spent on meaningful and productive activities, or "wasted".
The team found more free time was not necessarily better when considered against imagined feelings of wellbeing, stress or productivity. More specifically, imagined wellbeing plateaued as hypothetical productive free time rose from moderate to high amounts, but was 0.4 points lower on a seven-point scale compared with moderate amounts of non-productive free time.
The team said the size of the effects was small and the optimal amounts of free time inexact. Nonetheless, they said the work suggested people who feel they have too little free time should not quit all of their obligations, but instead try to find a couple of leisure hours a day. Meanwhile those with empty days should try spending their time with purpose, be it connecting with others or doing something productive.
Andrew Oswald, a professor of economics and behavioural science at the University of Warwick who was not involved in the study, welcomed the research. "This is a valuable study because it provides all sorts of statistical evidence for a very intuitive idea: human beings like having spare 'discretionary' time - for leisure, home chores, hobbies, etc - in their day but not too much of it," he said. "It's a Goldilocks result - on time."