There is a meta analysis coming to close conclusion: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8641133/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8641133/

There is a meta analysis coming to close conclusion: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8641133/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8641133/ The interesting part being it's done on children still in their learning phase. The current article targeting 11000 makes me think it's done in a similar setting (catching 11000 adult working people for a study is just complicated). In general when people are arguing about side effects of bilingualism, I think they care more about adults who more or less reached their full potential.