This point of view on bilingualism is very much different from the perception and understanding of the same through the 20th century. Most of the researchers and policy makers in the last century considered that learning foreign language such as Russian or French hinders a child's development, both academically and intellectually. Some also believed that it acts as interference. Although they were not entirely wrong about it being interfering, but the latest studies conducted in the last few years on monolingual and multilingual people have gone on to provide enough evidence that bilingual and multilingual people's brains have both or all languages active even when they are speaking one language. This can act as an obstruction to the other system but this so called interference should not be treated as a hindrance but actually a blessing in disguise. The reason behind it is the fact that it actually forces the brain to develop its internal conflicting skills and simultaneously strengthens its cognitive muscles.
Studies have indicated that bilingual people are much more adept at solving different types of mental puzzles compared to their monolingual counterparts. They are quicker at performing mental tasks. These studies have also indicated that the bilingual people have more developed executive function. Executive function is actually a command system located in the brain that is utilized for the purpose of solving problems as well as performing a variety of mental tasks. It also includes will power and the ability to keep distractions at bay to stay as much focused to a particular task or goal as one possibly can. In addition, it also involves the process of switching attentions willfully and holding certain set of information in mind while ignoring the others which the brain thinks is less important.
So how does this struggle between two active language systems improve cognitive abilities? A lot of researchers used to think that bilingual people have the ability for inhibition that actually gets developed through the suppressing of the other language system on a regular basis. But the latest studies contradict this belief as many studies have concluded that bilinguals are better than monolinguals even at those tasks which do not require any sort of inhibition.