YOU BECOME LEFT HANDED ALREADY IN THE WOMB

A survey with a three-dimensional ultrasound shows that at the fourth month of gestation the fetus already moves with a preference for the right hand or the left

You are left-handed or right-handed already in the womb. Researchers from Trieste and Padua have seen this by following the movements of 29 fetuses with a three-dimensional echograph for 20 minutes each time. And they found that at the eighteenth week of gestation (4 and a half months) the children used their favorite hand for precision movements such as touching their mouths and eyes or, more freely, punching the uterine wall. For parents it can only be a curiosity to know in advance whether the son or daughter will be left-handed or right-handed, as well as whether it is female or male. However, the research dissuades from the attempt, which was always implemented until a few decades ago, to correct who is left-handed and do a right-handed.

THE HAND TIED

He tells a fifty-year-old: «I am a left-handed by nature, that’s why in my elementary school; my left hand was tied behind my back to force me to use my right hand. It was considered a defect to be removed. ” “Our research shows that one trend rather than the other is well rooted, it sinks into genetics, ” explains Dr. Valentina Parma, a researcher at the International School of Advanced Studies (SISSA) in Trieste, who signs the study with Umberto Castiello , professor of psychobiology and physiological psychology at the University of Padua.

CHECK THE NINE YEARS

Published in Scientific Reports, the survey had the final stage nine years later, when it was verified in the children and in the little girls by now big boys, above all able now to write, if the prediction coming from the US uterus had come true. Parma still says: «Yes, the prediction has come true. Of the 29 examined 25, they were confirmed right-handed and 4 left-handed. This is part of the general population where about 90% is right-handed.

THE DISORGANIZED BABY

Tells the researcher of Sissa that just born, emerging from the amniotic fluid and entering an environment dominated by the force of gravity, the newborn loses the motor skills so advanced and precise that he had in the belly of the mother and must reorganize . It will take four months for the baby to grasp an object, a few years to draw, other years to write, fully demonstrating what his favorite hand is.

PATHOLOGIES FROM ASYMMETRY

The predictive capacity of the method used by researchers in Trieste and Padua seems a good starting point for the early detection of pathologies characterized by brain asymmetries, such as depression, schizophrenia and autism spectrum disorders. «In fact one of the reasons for the research was to verify the possibilities of fetal kinematics », concludes Valentina Parma. And this fetal kinematics could lead to identify new markers to intervene at an early stage on developmental problems.