Researchers compared bilingual individuals and people who only knew one language and found that speaking multiple languages boosts a person's cognitive ability to an extent. Their findings indicate that on average, bilingual people delay the onset of Alzheimer's four more years than unilinguals. Bilingual children have also been found to be more skilled at prioritization and multi-tasking! The effect is greatest for people who have to switch between two languages every day, but merely knowing a secondary language also has its benefits.
The team is now determining whether bilinguality results in any sort of physical changes to the brain. Their early findings have shown that learning more than one language may actually increase the size of the brain!