Why righties and lefties

The world has gotten progressively more accepting of left-handed folk, but there are still some undeniable bummers associated with a left-handed proclivity: desks and spiral notebooks pose a constant battle, scissors are all but impossible to use and—according to some studies—life-expectancy might be lower than for right-handed people.

In fact, scientists have speculated for years that a single gene could control a left-right preference in humans. Now, in a paper published today in PLOS Genetics a group of researchers have identified a network of genes that relate to handedness in humans.

In previous studies, the researchers observed that patients with dyslexia exhibited a correlation between the gene PCSK6 and handedness. The lengthy list of left-handed leaders includes four of the last seven commanders in chief — President Obama, Bill Clinton, George H. Should right-handed presidential wannabes fake it? But one recent Dutch study suggests that left-handed politicians actually have an advantage in televised debates.

Golf legend Phil Mickelson, tennis ace Rafael Nadal, boxing champ Oscar de la Hoya — did you know that a number of your favorite sports superstars are lefties? Actually, left-handers may have the advantage in sports that involve two opponents facing each other, such as in tennis, boxing, and baseball, according to an MSNBC review of the book The Puzzle of Left-Handedness, by Rik Smits.

The author chalks it up to the fact that left-handed athletes get a lot more opportunity to practice against right-handed opponents than vice versa since there are so many more righties out there. For the study, participants watched an eight-minute clip from the frightening film Silence of the Lambs. When asked to recall events from the segment, lefties were far more likely to show signs of post-traumatic stress disorder than righties, including giving fragmented descriptions and making more mistakes.

According to a small study published in the Journal of Nervous and Mental Disease , lefties are more prone to having negative emotions. In addition, they seem to have a more difficult time processing their feelings. Again, this seems to be related to the brain-hand connection.

Compared to righties, left-handed participants in the study showed an imbalance in activity between the left and right hemispheres when trying to process their moodiness. Lefties may get bent out of shape, but research shows they're just a bunch of bashful self-observers. When scientists from Abertay University in Scotland gave 46 lefties and 66 righties behavioral tests to measure their impulsiveness and personal restraint , the left-handers in the group more commonly agreed with statements like "I worry about making mistakes" and "Criticism or scolding hurts me quite a bit.

For years, myth has held that left-handers are more likely to become alcoholics. Research into the topic was murky, however, and relied on small samples. But a survey of more than 25, people from 12 countries has cleared things up a bit. While lefties are not more prone to alcoholism , they do drink more often.

Researcher Kevin Denny, who examined the data for a paper published in the British Journal of Health Psychology , says the main takeaway should be debunking that whole left-handedness-alcoholism link.

There have been eight left-handed US presidents, which is double the rate that would be expected from the general population. Left-handed athletes also tend to perform better than their right-handed counterparts.

Left-handed boxers do well for this reason, as do left-handed tennis players. Left-handed baseball pitchers are prized because they have an advantage.

However, you almost never see left-handed catchers. The last left-handed catcher in major league baseball was Benny Distefano, who played in Likewise, there are almost no left-handed quarterbacks. Tua Tagovailoa who plays for the Miami Dolphins is the first left-handed quarterback to play a single down in the NFL since This mostly has to do with the fact that how a quarterback throws has implications for the entire team.

It probably has something to do with the bain, and maybe there is a genetic component, and maybe it has something to do with development in the womb. Regardless of why it happens, just make sure to keep your eye on any left-handed people you know. I heard they are all sinister. The issue of hand dominance is a really weird one. That being said, here is what we do know about handedness. The bible talks of being seated at the right hand of God, which is the position of favor.

So, why do we have this imbalance? The problem is, no one has found any gene that could be the handedness gene. Both of my parents are left-handed, but my brother and I are both right-handed. In fact, no species of simians show any hand preference. There is a flip side, however. The crown of your head is the area at the very top of your skull. Learn about health conditions that may affect this area. Health Conditions Discover Plan Connect. Type 2 Diabetes. Are Left-Handed People Smarter?

Medically reviewed by Deborah Weatherspoon, Ph. A history of left-handedness. What does the research say? What else should I know about handedness? What else should I know about intelligence? Are any other traits associated with left-handedness?

The takeaway. Read this next. Left Brain vs. Medically reviewed by Debra Sullivan, Ph. What Is the Hilum of the Lung?