The Myth of Multitasking

Everyone has no doubt heard something along the lines of “young people today are more adept at multitasking”. You may also have heard more specific variations on this such as “students studying a certain subject” and “people from a certain country“ are better at multitasking than others.
The problem with such statements is they fly in the face of evolutionary biology. It takes many generations of a species’ evolution before real changes begin to emerge. Young people, students of certain subjects and people from certain countries are working with the essentially same brains as the rest of us. Brains have not magically changed in one generation.
Genetic factors are one thing but what about the environment? That also influences behavior. And of course the big thing that has changed in the environment is the technologies we use. So the argument may go that because someone has become proficient with a technology they have in effect supplemented their brain power in a way that makes them better multitaskers. 
One of the first scientists to sound the alarm on this kind of thinking was Clifford Nass. He talks about the problem and its relationship with technology in this NPR interview.

The basic message from the scientific research is that rather than multitask we rapidly switch between the serial processing of tasks. There is an extra load involved in performing the switch. Those who think they are good at multitasking are actually fooling themselves. Attempting to multitask demonstrably diminishes performance on each individual task. This is something that instructors may need to emphasize with their students, particularly when it comes to studying for exams. 

Additional reading and listening:

You Say Multitasking Like It’s a Good Thing by Charles J. Abaté
Think you are multitasking? NPR audio