Have you ever asked yourself how many left-handed people in the world? Do you yourself belong to this select group inhabiting planet Earth? Can you predict before birth if your son/daughter will be left-handed? In the following animation for TED-Ed, Daniel M. Abrams discusses how the unequal relationship between left and right handed has allowed human evolution has occurred within a balance between competitiveness and cooperation.
One tenth of the world’s population is left-handed. This phenomenon is not new. In fact, some paintings, tools and utensils of antiquity have shown that left-handed people had already lived 500,000 years ago.
Left-handedness is the natural tendency to preferentially use the left side of ones body, either hand or foot. It is a minority phenotype of the human species. People who use the right hand preferably are right-handed, while interchangeably using both hands or legs are ambidextrous.
Studies indicate that you can find out if a baby is left-handed or not as the position of the fetus in the womb. The reality finds that identical twins with the same genes can have different dominant hands, just as happens with other brothers.
However, the possibility of handedness depends on the dominant hand of parents. Passing combinations:
– Father and mother prefer right hand, you have a 17% chance of being born left-handed.
– With both skilled parents, the possibility of being born left-hander is only 10%.
– Mother left-handed and right-handed father, you have a 22% chance of being born left-handed.
– With two left-handed parents, the chance of being born left-handed only increases to 25%.
Scientists attribute to evolution and natural selection that there is this small proportion of left-handed people. Theories point to a matter of being competitive forces balance and collaborative forces in human evolution.
And what about the benefits of being left handed? Studies indicate a small correlation between left-handed people and greater creativity-intelligence. This may be due to the habit of having to adapt and create own resources from the child’s personal use. And, the 10% minority population left foot, also explains why most of the utensils and tools are made for right. It explains why these people are more ‘awkward’ with certain tools and suffer more accidents.
On the other hand, in the activities in which there is a clear advantage of left-handed people it is clear: tennis, boxing, baseball hitters, even football … Here, in the surprise factor is the key. However, despite the imbalance between left-handed/right-handed, explains Daniel M. Abrams TED-Ed for the unequal relationship between left and right handed has contributed to human evolution and occurred within a balance between competitiveness and cooperation.