What does left handed mean

But researchers have found that in populations with certain mental disorders, that rate goes up. Previous studies have found that people with psychosis had a 20 percent likelihood of being left-handed, though a small study in the journal SAGE found the rate of psychotic lefties may be even higher. For those with mood disorders such as depression or bipolar disorder , the rate of left-handedness was close to average, at 11 percent.

But in people with psychosis, such as those with schizophrenia or schizoaffective disorder, the rate of left-handedness was 40 percent, well above average. Researchers theorize brain laterality plays a role. Scientists have also found an increased risk for dyslexia, ADHD , and certain mood disorders in left-handed people, according to a study published in Pediatrics.

Researchers are not exactly sure how to explain this phenomenon, but many believe it's related to how the brain is wired. Your noggin is divided into two halves: the left side and the right side. Most people righties and lefties alike rely on the brain's left hemisphere for tasks like language functioning. But about 30 percent of left-handed folks are either partial to the right hemisphere or have no dominant hemisphere at all. According to scientists, having one hemisphere dominate is much more efficient, which is why some left-handers are at increased risk for learning impairments and brain disorders.

But lefties may be in luck when it comes to other health conditions: Results of a large survey published in the journal Laterality found that left-handers had lower rates of arthritis and ulcers. People who use their left hands when listening may more easily hear slowly-changing sounds than those who use their right hands, according to a study from Georgetown University Medical Center.

The researchers who conducted the study, presented at Neuroscience , found that the left and right hemispheres of the brain specialize in different kinds of sounds. The left hemisphere, which controls the right hand, likes rapidly-changing sounds like consonants, while the right hemisphere, which controls the left hand, likes slowly-changing sounds like syllables or intonation.

According to the researchers, if you're waving an American flag while listening to a presidential candidate, the speech will sound slightly different to you depending on whether you're holding the flag in your left or right hand. The research could ultimately result in better treatment for stroke and language disorders. University of Kansas researchers recently determined the handedness of ancient humans by studying -- oddly enough -- their teeth. The study, which was published in the journal Laterality, found that when our great-great-great-great- you get the point -grandfathers processed animal hides, they would hold one side of the carcass in one hand and the other in their mouth.

By locating the wear and tear on those prehistoric chompers, scientists were able to determine whether our prehistoric ancestors were using their left hand or right hand more dominantly. The results? Southpaws have been bragging about their creative clout for years. To determine whether lefties were more likely to pursue creative careers than righties, the folks behind the Left-Handers Club a pro-leftie group dedicated to left-handed research and product development surveyed more than 2, left-handed, right-handed, and ambidextrous participants and found that lefties tended to find advantages and be drawn to careers in the arts, music, sports, and information-technology fields.

The lengthy list of left-handed leaders includes four of the last seven commanders in chief -- President Obama , Bill Clinton, George H. First Known Use of left-handed 15th century, in the meaning defined at sense 1. Learn More About left-handed. Time Traveler for left-handed The first known use of left-handed was in the 15th century See more words from the same century.

From the Editors at Merriam-Webster. Statistics for left-handed Look-up Popularity. Style: MLA. English Language Learners Definition of left-handed. Kids Definition of left-handed. Medical Definition of left-handed.

Get Word of the Day daily email! Test Your Vocabulary. Test your vocabulary with our question quiz! However, being left-handed is really nothing to fret about. Over time, technology and medicine have advanced so much and has managed to improve childbirth processes. But despite this, the amount of people who are left-handed remains the same, and it still fails to provide an explain why human are by default born as right-handed. The theory of parental pressure aims to explain why right-handedness is the dominant main hand.

The theory is that since most parents who brought up up their children are right-handed, we, therefore become mostly right handed. But this theory has some downfalls, in that it still does not answer the question of how the dominant hand was the right dominance began, and why handedness is more related to biological parents, and not adoptive parents.

Another theory about handedness is social stigma and repression of left-handedness. Since the beginning of time, being left-handed was seen as a negative thing to be.

Despite this, there have been many very famous and successful left-handed people, and it been shown that in some cases it can be related to genius characteristics, as well as unique artistic and visual talents. In Taiwan, until only recently, if people were left-handed they were pushed to try to be right-handed or were pushed to use their right hand.

This is because it is a lot more challenging to write Chinese letters with the left hand. In every language, it varies. In Latin, it is less of a struggle to write with the left hand, and in Arabic and Hebrew which goes from right to left is even easier to be written with the left hand.