A strong handshake can indicate power, confidence or aggression, and now scientists have found that the strength of a person's grasp may also be one of the most useful ways to measure their true age.
Scientists at Stony Brook University in the US and the Institute for Applied Systems Analysis (IIASA) in Austria found that hand grip corresponds to other markers of ageing such as people's future mortality, disability, cognitive decline and ability to recover from hospital stays.
For the new research, IIASA researchers Warren Sanderson, Professor of Economics with joint appointment in History at Stony Brook and Serguei Scherbov reviewed findings from over 50 published studies that focus on people around the world and of all ages.
"Hand-grip strength is easily measured and data on hand-grip strength now can be found in many of the most important surveys on ageing worldwide," said Sanderson.
The study demonstrated how such a test could be used as a measure for ageing to compare different population groups. The study used data from one such survey, the United States Health and Retirement Survey (HRS), to show how this could be done.
"We found that based on this survey, a 65-year-old white women who had not completed secondary education has the same handgrip strength as a 69-year-old white women who had completed secondary education," Scherbov said.
"This suggests that according to a handgrip strength characteristic their ages are equivalent and 65 year-old women ages 4 years faster due to lower education attainment," Scherbov said.
The study is published in the journal PLOS ONE.