Lefties think quicker but more likely to carry gene linked to schizophrenia

Recent research suggests that left-handed people may have the upper hand on right-handed people when using fine motor skills and thinking quickly, but left-handed people also may carry a gene linked to schizophrenia.

In the New York Times article, psychologists suggested that hand dominance is related to brain asymmetry and lateralization.

“I thought it was an interesting review of some issues related to lateralization in the brain,” said Roxanne Prichard, a St. Thomas psychology professor who specializes in neuroanatomy, sleep and circadian rhythms.

Lateralization is when one brain hemisphere’s structure and function is distinct from the other hemisphere, she added.

Oxford researchers found that left-handed people may be more likely to have a gene named LRRTM1. According to a Molecular Psychiatry article, Oxford researchers found that people with the gene have an increased chance of being left-handed. The study found LRRTM1 gene carriers are slightly more at risk of developing psychotic mental illnesses, such as schizophrenia.

Prichard explained her opinion on the article’s description of health-related issues and how they correlates with handedness: “A reader might understand from the article that some of the genes related to schizophrenia were more common in left-handed people, but it’s not necessarily meaning that left-handed people have a higher chance of schizophrenia.”

But she added, “There are a number of conditions that left-handed people do have a higher percentage chance of.”

In the New York Times article, Daniel Geshwind, University of California professor of human genetics, neurology and psychiatry, said handedness is genetic.

“Handedness has a genetic basis, but like other complex traits – height, weight – it is complex,” he said. “It’s not a single gene that leads to it.”

Sophomore Derek Smith, who is left-handed, said he could see how left-handedness could be genetic because his brother and dad are left-handed.

But sophomore Richard Shallbetter said he didn’t agree with the finding that handedness was genetic because his twin brother is right-handed, and he has no other immediate left-handed relatives.

Left-handers on campus

Some St. Thomas students and faculty claim the campus has a “right-hand” design. According to a recent New York Times article, 10 percent of the human population is left-handed, and the dominant right-hand design is a common trend.

Right and left-handed desks on campus.
Right and left-handed desks on campus. Some students and faculty claim St. Thomas has a right-hand design. (Hannah Anderson/TommieMedia)

Prichard said St. Thomas’ left-handed people are affected by the right-hand design of campus.

“Some of the desks, most scissors, etc., are for right-handed people, [and] the way microscopes are set up with where the computer is versus where the scope controls are,” Prichard said.

Smith agreed a lot of designs are right-handed.

“Right-handed chairs are kind of annoying. Notebook spirals always get in the way, and I hate the smudges I get after writing a lot of notes,” Smith said. “It would be easier to be right-handed just because everything is universally built toward right-handed people.”

Shallbetter agreed.

“If I was right-handed, I wouldn’t have to smudge the lead or ink across the page as I wrote,” Shallbetter said.

An article in Neuropsychology by Australian National University researchers found that left-handed people think quicker when playing computer games or competing. The researchers hypothesized that part of the difference could be due to increased connections between the brain hemispheres of left-handed people.

Freshman Michaela Smith said her left-handed friends were quick thinkers.

“A couple of my left-handed friends are engineers, and they are just really good with numbers,” Smith said. “They can just pull it right off the top of their head without any problem.”

She also said one of her left-handed friends has an advantage in playing baseball, which correlates with University of Montpellier research that found lefties had an advantage in certain sports.

The article suggests further research is needed to understand the development of the brain. Oxford University researcher Clyde Francks said hand dominance is mysterious.

“[Hand dominance] is not at all understood,” Francks said. “We’re really at the very beginning of understanding what makes the brain asymmetrical.”

Hannah Anderson can be reached ande5385@stthomas.edu.