What determines being left or right handed? As a scientific question might seem irrelevant, but actually handedness is a good example of a brain phenomenon called lateralization which basically refers to the location of certain brain activities to one brain hemisphere or the other (for example, language areas are located in the left hemisphere). There is evidence for genetic factors playing a determining role in lateralization. What’s more, this asymmetric gene expression is supposed to already be taking place during fetal development. However, a number of questions were still unanswered like how is it possible that in fetuses where the motor cortex is still not functionally linked to the spinal cord, there are asymmetries in arm movements in the womb. Therefore an international group of researchers set to find out whether the root of handedness did lie in the cortex or elsewhere, more specifically in the spinal cord. Keep on reading on mappingignorance.org