Tests carried out on a group of native English speakers suggest that learning an additional language slows down the decline of thinking skills in later life.
The study was carried out by researchers from the University of Edinburgh, who examined the results of intelligence tests taken by a group of individuals who were born in 1936.
The 853 people tested were part of the Lothian Birth Cohort 1936. All born and raised in Edinburgh, they took part in the Scottish Mental Survey of 1947 – when they were 11.
They were then tested again between 2008 and 2010 (when they were in their 70s), for changes in reasoning, memory, speed of thinking, fitness and health, eyesight and blood composition.
The research team who studied the results of both tests found that those who spoke two or more languages had significantly better thinking skills in later life compared with what would have been expected from their childhood IQ scores.
This was the case whether individuals had learned a second language before the age of 18 or later on in life.
“These findings are of considerable practical relevance,” said Dr Thomas Bak, from the University of Edinburgh’s Centre for Cognitive Ageing and Cognitive Epidemiology, who led the study.
“Millions of people around the world acquire their second language in later life. Our study shows that bilingualism, even when acquired in adulthood, may provide a small benefit to the ageing brain.”
The research, entitled Does Bilingualism Influence Cognitive Ageing? and funded by Age UK, was published in the medical journal Annals of Neurology.