the hand bone's connected to the spine bone
It might not be all in your head after all. A small team of biopsychologists from Ruhr University Bochum, in Germany, believes they have found evidence proving that whether you are right- or left-hand dominant comes from genetic activity in the spine, not just the brain, Science Alert reports.
Previously, researchers believed that gene activity in the right or left hemisphere of the brain resulted in a person's handedness. Scientists knew that such a preference starts in the eighth week of pregnancy, with unborn children preferring to suck on his or her right or left thumb by week 13.
That's where the new research comes in:
Arm and hand movements are initiated via the motor cortex in the brain. It sends a corresponding signal to the spinal cord, which in turn translates the command into a motion. The motor cortex, however, is not connected to the spinal cord from the beginning. Even before the connection forms, precursors of handedness become apparent. This is why the researchers have assumed that the cause of right respective left preference must be rooted in the spinal cord rather than in the brain. [Ruhr-Universität Bochum]
"These results fundamentally change our understanding of the cause of hemispheric asymmetries," the authors of the study wrote.
And as Science Alert notes, the study is still very small and early to throw out all previous assumptions. That being said, "it's definitely intriguing new evidence that scientists will need to investigate further."