Around 13% of men and 11% of women are left-handed. Their brains are wired differently and they are a minority in a predominantly right-handed world. This makes them a subject of interest to researchers in a variety of fields. Here are eight science-backed facts about left-handers that may surprise you.
1. They’re more intelligent
A study presented at the American Psychological Association’s annual conference found that left-handers tend to be brighter than right-handers. Researchers enlisted 1,200 participants and determined their degree of left-handedness by asking a series of questions such as ‘which ear do you use to listen to another person’s heartbeat?’ Those who did everything with the left side of their body were classified as ‘true’ left-handers. They scored a third better on vocabulary tests than right-handers or ambidextrous people and twice as well on problem-solving tasks. In addition, more of them were intellectually gifted, with IQs over 140.
2. They have a higher risk of schizophrenia
A study carried out at Yale University assessed 107 patients at psychiatric clinics. About 10% of those being treated for bipolar disorder or depression were left-handed, a rate corresponding to the prevalence of left-handedness in the general population. But a striking 40 percent of people with schizophrenia and related psychotic disorders were left-handed. Although the majority of left-handers do not develop schizophrenia, researchers theorize that changes in the brain that make people left-handed may also put people at higher risk for the illness.
3. They are more affected by fear
In a study presented at the annual conference of the British Psychology Society, participants were asked to watch an eight minute film clip from ‘The Silence of the Lambs’. They were then asked to verbally recall events from the scary segment. The left-handed participants gave more fragmented and repetitive accounts than the right handed ones. The same errors in verbal recall are commonly observed in people with post-traumatic stress disorder. Within the general population, left-handed people are nearly twice as likely to suffer from PTSD. Researchers theorized that left-handers may be more affected by terrifying scenes because they are right-brain dominant and the right side of the brain is involved in processing fear.
4. They have a fighting advantage
One of the most interesting facts about left-handers is that they enjoy above average success in sports where two opponents face each other. For example, 5 of the top 25 international tennis players are left-handed, and so are 7 of the 16 top world fencers. This could be because left-handers are used to playing right handers, whereas right handers get less practice with left-handed opponents. Researchers at the University of Montpellier wondered if this same advantage would have helped left-handers to fight for survival and mates in prehistoric times. They surveyed nine primitive societies in five separate continents and found that left handers thrive and multiply in tribal groups with high levels of violence. Among the Eipo of Indonesia, where there are three murders per 1000 people a year, 27% of the population is left-handed.
5. They are more inhibited
A study at Abertay University found that left-handers are more likely to feel anxious, embarrassed or shy about doing or saying what they want. Researchers gave a behavioral test to 46 left-handed and 66 right-handed participants. The test used a series of statements to measure personal restraint and impulsiveness. The left-handers tended to agree with statements ‘I Fear of making mistakes‘. Overall, left-handed people scored higher when it came to inhibition, especially in new or unusual situations. Researchers believe this could be because the right half of the brain, which is dominant in left handers, controls negative aspects of emotion.
6. They have better memories
Researchers from the University of Toledo performed two studies looking at episodic and factual memory. The first discovered that individuals who had been left-handed, or had left-handed relatives, could recall events more readily. At a follow up study, the scientists discovered that if words were introduced to a half of their mind, participants recalled facts better and if they had been demonstrated to both parts of their brain, they recalled occasions improved. The researchers concluded that the key to remembering events may lie in the corpus callosum which connects the two halves of the brain. The corpus callosum tends to be larger in left-handed people and those with left-handed relatives.
7. They have a political advantage
Famous left-handed leaders include four of the last seven U.S. presidents: Barack Obama, Bill Clinton, George W. Bush, and Gerald Ford. Research suggests that left-handed politicians have an advantage in televised debates. Scientists from the Max Planck Institute analyzed statements made by presidential candidates in the 2004 and 2008 elections. The candidates tended to gesture with their dominant hand when saying something optimistic. People unconsciously associate good things with their dominant side. Since television presents a mirror image, 90% of viewers (the right-handed ones) are apt to feel that the left-handed candidate’s gestures are more positive.
8. They have been in the minority for 500,000 years
A University of Kansas study has found evidence that ancient Homo species, living more than 500,000 years ago were predominantly right handed. When processing animal skins, early people could stretch the mask by holding a single facet in their hand and another in their mouth. The scientists were able to determine whether our prehistoric ancestors were left or right handed by examining their teeth. They looked for scrapes caused by a stone tool scraping across the front teeth while working a hide. If the hide was held in the right hand, scratches went from the upper-left side of the tooth to the lower-right side. If it had been held in the left hand, the scratches showed the reverse pattern. Most of the teeth of Neanderthals and older species of hominids showed a right-handed scratch pattern.
These are the 8 extraordinary scientific facts about left-handers we know. If we have left some to cover, please let us know by leaving your comments below. Cheers!!
