Studies have claimed that bilinguals outperform monolingual speakers on several cognitive performance measures, have delayed onset of dementia (by four to five years) and higher intelligence.
The thought is that bilinguals may be better at inhibition since they have to constantly suppress their second language while speaking. Additionally, they may perform better on switching between tasks from their experience switching between languages.
However, the lack of reproducibility and small sample sizes in these studies are problematic as far as credibility goes. Furthermore, there is a huge publication bias: 68% of positive studies were published, whereas only 28% of negative studies were published.
Does being bilingual enhance cognition, or is it a person’s cognitive ability that allows one to learn multiple languages?
Regardless of increased intelligence or cognitive ability, learning multiple languages has several benefits: it can be advantageous for career development, make travelling easier and more gratifying, enable a profound understanding of another culture and the world from a different perspective.