That is a worry for Japan, which is aging far faster than any other developed country.

"One misconception of aging research is that we are looking to prevent aging, " says Sinclair.

The study findings were published recently in both the Journal of Gerontology: Psychological Sciences and Psychology and Aging.

He prefers to look at an international sample rather than data on single countries, because that enables more robust identification of the impact of ageing.

We need to further reduce our ratio of public debt to GDP to give us the flexibility to meet the demands of our aging population.