Previous research from other groups has indicated that Alzheimer's disease has a later onset in bilingual or multilingual groups. There is also research which

Previous research from other groups has indicated that Alzheimer's disease has a later onset in bilingual or multilingual groups. There is also research which shows that led poisoning affects higher IQ people slower, that is unless the led poisoning is high enough and then it's suddenly horrible. Thus what I personally suspect is that the brain is very flexible and can sacrifice things like multilingualism and higher IQ to delay damage affecting more primitive brain functions. But that's all it is, delay.