This New York Times article by Yudhijit Bhattacharjee provides a summary of a variety of research evidence on the benefits of bilingualism. The author summarizes research benefits in young children and the elderly and provides a new way to see bilingualism as an edge! Benefits include:
Better cognitive skills in general
Better/improved executive functioning
Shielding from Dementia and Alzheimers
Stimulating on the areas of the brains that improves functioning not seen in monolinguals
Speed in processing and shielding of distractions
Increased ability to monitor the environment
This is a great must read!