Handedness Developed in the Womb?

Whether you are left or right handed can have a big impact on your education with left handed children placed at a significant disadvantage in right handed world (The Effect Of Environment And Handedness On Writing Performance ). Why people favour one hand, ear, foot or eye is still a mystery but a recent study by Professor Peter Hepper at the Queen’s University, Belfast School of Psychology suggests that handedness may develop in the womb.
By studying ultrasound scans the team found that nine out of ten fetuses preferred to suck their right thumb at fifteen weeks gestation. Following up the children when they were ten years old found that all the right thumb suckers went on to be right handed where as ten of the fifteen left thumb sucking fetuses were left handed.
More details can be found in the New Scientist.
For more information on how left / right domiance of hand, eye, ear and foot can effect behavior, check out Carla Hannaford’s book The Dominance Factor.