The team used an algorithm that took into account participants’ responses to a host of different metrics, from the difficulties they had with everyday activities to their scores on cognitive tests, to determine whether they were likely to have dementia. They then split the participants into eight different cohorts, representing different generations. Participants were also split into six age groups. As expected, the researchers found the prevalence of dementia increased by age among all birth cohorts, and in each of the three regions: UK, US and Europe. However, at a given age, people in more recent generations were less likely to have dementia compared with those in earlier generations.