Can I get any smarter than I already am?

To show you the power you have to exercise your brain, look at a study measuring the brain size of London cabbies. Why cabbies? Despite the impression you've gotten from the profanities they hurl at jaywalkers, cabbies have a very neurologically taxing job. They have to memorize the complex layout of a city and be able to figure the fastest routes between thousands of different starting and finishing points. The results of the research: the cabbies with the most experience-and therefore the ones who kept innovating to get more rides-continually taxed their brains to survive in the competitive industry and actually had larger right temporal lobes. They built bigger brains because they used it so often-and in different ways every day.