In the study conducted by the Henry Ford Health System in Detroit, more than 70 percent of participants held their cellphones up to the ear on the same side as their dominant hand.
Left brain dominant people -- those whose speech and language center is on the left side of the brain -- are more likely to use their right hand for writing and other everyday tasks, including holding a cellphone, the study found.
This practice, researchers said, appears illogical since it is challenging to listen on the phone with the right ear and take notes with the right hand.
Similarly, right brain dominant people are more likely to use the left hand to hold the phone, the researchers found.
"Our findings have several implications, especially for mapping the language center of the brain," Michael Seidman, director of the division of otologic and neurotologic surgery at Henry Ford, said.
The study also may offer additional evidence that cell phone use and brain, and head and neck tumors may not be linked, he said.
If there was a strong connection, Seidman said, there would be a far more people diagnosed with cancer on the right side of their brain, head and neck -- the dominate side for cell phone use -- but no correlation has been found.
Among those in the study who were right handed, 68 percent reported they hold the phone to their right ear, while 25 percent used the left ear and 7 percent used both right and left ears
For those who were left handed, 72 percent said they used their left ear for cellphone conversations, while 23 percent used their right ear and 5 percent had no preference.
The study concerned just cellphones and no attempt was made to compare or contrast with preferences when using landline handsets, the researchers said.