Initially it was assumed that people who were right handed had left-hemisphere dominant brains but studies have shown that in more than 95 percent of right handed people, the left hemisphere of the brain handled language while the right hemisphere handled emotion and image processing. However such a strict division was visible in just 20 percent of left handed people.
In an attempt to come up with a more accurate way of predicting brain hemisphere dominance, researchers at Henry Ford Hospital in Detroit studied the cell phone usage habits in more than 700 people and found that when hearing capacity of both the ears are the same and a person holds his cell phone to his right ear, then the left hemisphere of his brain is more likely to be dominant.
"Our findings have several implications, especially for mapping the language center of the brain. By establishing a correlation between cerebral dominance and sidedness of cellphone use, it may be possible to develop a less invasive, lower-cost option to establish the side of the brain where speech and language occur rather than the Wada test", lead researcher Michael Seidman said.