Being left-handed isn’t that rare after all! Scientists claim one in five people could be leftie after the biggest study ever into the genetic trait
- Study of more than two million people looked into how common lefties are
- Used different criteria to define what being left-handed actually means
- Found the figure could be as low as 9.34 per cent or as high as 18.1 per cent
Being left-handed may not be as rare as it is thought, according to the biggest study ever to look into the genetic peculiarity.
Scientist found around one fifth (18.1 per cent) of all people could be left hand dominant — but say the figure could be as low as 9.34 per cent.
Understanding what causes left-handedness is a long-standing mystery of human evolution and genetics.
Scroll down for video
Understanding what causes left-handedness is a long-standing mystery of human evolution and genetics. A landmark study found the figure could be as low as 9.34 per cent or as high as 18.1 per cent (stock)
The study was based on an analysis of more than two million people from five different studies by an international team led by the National and Kapodistrian University of Athens and the University of St Andrews.
The differing estimates come from what the researchers define handedness as.
For example, 9.34 per cent of people use their left hand only for manual tasks.
But the most lenient criteria for being a leftie states 18.1 per cent of people are left-handed.
The research will help scientists understand more about how physical and psychological factors contribute to handedness.
Co-lead author Dr Silvia Paracchini, of the School of Medicine at St Andrews University, said: ‘This study will provide a useful reference for different areas of handedness research.
Being left-handed may not be as rare as it is thought, according to the biggest study ever to look into the genetic peculiarity. A study found up to 18.1 per cent of all people could be left hand dominant (stock photo)
‘In addition to providing reliable figures, the study highlights variability across studies depending on the different criteria used to measure handedness.’
Understanding handedness contributes to our understanding of human evolution, explained the researchers.
It has been shown in previous research that right-handedness is one of a handful of markers that separates humans from apes.
Added Dr Paracchini: ‘While we intuitively classify handedness as a left/right category, these data show the proportion of people using different hands for different tasks is almost as big as the proportion of the left-handers.’
A study last year found four genetic regions which may cause left-handedness, and they could also be the reason lefties have superior language skills.
The study of left-handed folk failed to identify any precise ‘left-handed genes’ but was able to narrow it down within the human genome to certain areas.
Researchers then found that left-handedness may be a byproduct of how the brain develops in the womb as well as the body’s microtubules.
These form the cells cytoskeleton, the internal scaffolding that does most of the heavy lifting within human cells.