I have no scientific data to back up my theory but I believe that which side of the brain people favor is loosely related to which hand people favor. Whether you are right handed or left handed, if you try to use the opposite hand for things like writing, signing your name or doing delicate precise tasks, chances are it won't turn out so well. The percentage of the population that can use their right & left hands equally is about 10%. This fact I actually looked up.
A temporary placement agent who specializes in the creative field told me that he believes that the percentage of people who can claim to be equally good at the artistic problem solving of design and the logic-based problem solving of programming is about 3%. Again this is not based on science but rather his observation. Most applicants who told him they could do both tasks fell far short of their claims in one of the areas when he sent them on an assignment.
So here is my question. Is it reasonable for an employer to expect an applicant to perform both the creative and programming aspects of interactice media? Or are these employers just being cheapscates expecting one person to do the work of a team?