Bilingualism has a positive effect on
cognition later in life, even for those who acquired the second language
in adulthood, researchers found.
While prior research has
investigated the impact of learning more than one language, ruling out
‘reverse causality’ has proven difficult.
The crucial
question is whether people improve their cognitive functions through
learning new languages or whether those with better baseline cognitive
functions are more likely to become bilingual, researchers said.
"Our
study is the first to examine whether learning a second language
impacts cognitive performance later in life while controlling for
childhood intelligence," said lead author Dr Thomas Bak from the Centre
for Cognitive Aging and Cognitive Epidemiology at the University of
Edinburgh.
For the study, researchers relied on data from the
Lothian Birth Cohort 1936, comprising 835 native speakers of English who
were born and living in the area of Edinburgh,
Scotland.
The participants were given an intelligence test in 1947 at age 11 years and retested in their early 70s, between 2008 and 2010.
Of
the participants reported to be able to communicate in at least one
language other than English, 195 learned the second language before age
18, and 65 learned it thereafter.
Findings indicated that those
who spoke two or more languages had significantly better cognitive
abilities compared to what would be expected from their baseline.
The
strongest effects were seen in general intelligence and reading. The
effects were present in those who acquired their second language early
as well as late.
"These findings are of considerable practical
relevance. Millions of people around the world acquire their second
language later in life. Our study shows that bilingualism, even when
acquired in adulthood, may benefit the ageing brain," said Bak.
The
findings are published in Annals of Neurology, a journal of the
American Neurological Association and Child Neurology Society.
