The test results pointed to "high multitaskers" being worse at it because the tests weren't designed well to measure multitasking ability, in fact they seem to be testing the OPPOSITE. From the BBC article:
[quote]
In the first, they were tested for their ability to ignore irrelevant information. They were briefly shown a screen with two red rectangles and either 0, 2, 4 or 6 blue rectangles.
The task was to determine whether, when the screen was shown again, one of the red rectangles had been rotated.
Low multitaskers were better at the task, regardless of the number of blue rectangles, whereas high multitaskers got worse at it as the number of distracting blue rectangles went up. [/quote]
What??
Obviously people who are WORSE multitaskers will be BETTER at ignoring the irrelevant information and focusing only on the rotation of the red rectangles. If they really wanted to test for multitasking ability they would ask for whether the red rectangles had been rotated, how many blue rectangles there were, and whether they were bigger or smaller than the last set.
The other two tests also seem to test the ability to focus on a single task rather than try to test what makes someone proficient at multitasking