Navigation Links
Shedding light on southpaws
Date:4/25/2012

Lefties have always been a bit of a puzzle. Representing only 10 percent of the general human population, left-handers have been viewed with suspicion and persecuted across history. The word "sinister" even derives from "left or left-hand."

Two Northwestern University researchers now report that a high degree of cooperation, not something odd or sinister, plays a key role in the rarity of left-handedness. They developed a mathematical model that shows the low percentage of lefties is a result of the balance between cooperation and competition in human evolution.

Professor Daniel M. Abrams and his graduate student Mark J. Panaggio -- both right-handers -- are the first to use real-world data (from competitive sports) to test and confirm the hypothesis that social behavior is related to population-level handedness.

The results are published today (April 25) in The Journal of the Royal Society Interface.

"The more social the animal -- where cooperation is highly valued -- the more the general population will trend toward one side," said Abrams, an assistant professor of engineering sciences and applied mathematics at the McCormick School of Engineering and Applied Science. "The most important factor for an efficient society is a high degree of cooperation. In humans, this has resulted in a right-handed majority."

If societies were entirely cooperative everyone would be same-handed, Abrams said. But if competition were more important, one could expect the population to be 50-50. The new model can predict accurately the percentage of left-handers in a group -- humans, parrots, baseball players, golfers -- based on the degrees of cooperation and competition in the social interaction.

The model helps to explain our right-handed world now and historically: the 90-10 right-handed to left-handed ratio has remained the same for more than 5,000 years. It also explains the dominance of left-handed athletes in many sports where competition can drive the number of lefties up to a disproportionate level.

Cooperation favors same-handedness -- for sharing the same tools, for example. Physical competition, on the other hand, favors the unusual. In a fight, a left-hander in a right-handed world would have an advantage.

Abrams and Panaggio turned to the world of sports for data to support their balance of cooperation and competition theory. Their model accurately predicted the number of elite left-handed athletes in baseball, boxing, hockey, fencing and table tennis -- more than 50 percent among top baseball players and well above 10 percent (the general population rate) for the other sports.

On the other hand, the number of successful left-handed PGA golfers is very low, only 4 percent. The model also accurately predicted this.

"The accuracy of our model's predictions when applied to sports data supports the idea that we are seeing the same effect in human society," Abrams said.

Handedness, the preference for using one hand over the other, is partially genetic and partially environmental. Identical twins, who share exactly the same genes, don't always share the same handedness.

"As computers and simulation become more widespread in science, it remains important to create understandable mathematical models of the phenomena that interest us, such as the left-handed minority," Abrams said. "By discarding unnecessary elements, these simple models can give us insight into the most important aspects of a problem, sometimes even shedding light on things seemingly outside the domain of math."


'/>"/>
Contact: Megan Fellman
fellman@northwestern.edu
847-491-3115
Northwestern University
Source:Eurekalert

Related medicine news :

1. Shedding light on why it is so tough to make healthier hot dogs
2. Private weight-loss surgery clinics shedding quality patient care
3. U.S. Gives Green Light to Publish Controversial Bird Flu Research
4. Scientific session and new research highlights
5. Presidential keynote address and new research highlights from the American Society of Pediatric Otolaryngology meeting
6. Pesticides May Be Linked to Slightly Smaller Babies, Shorter Pregnancies
7. NIH researchers highlight progress, path forward for developing TB vaccines
8. Lightheadedness Upon Standing Could Signal Heart Risk
9. The twilight zone of traffic costs lives at stoplight intersections
10. Watching Movie Stars Light Up May Spur Kids to Smoke
11. Wake Forest Baptist research sheds light on cancer of the appendix
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/23/2017)... BOSTON, MA (PRWEB) , ... June 23, 2017 ... ... Better Care Reconciliation Act (BCRA), their proposed healthcare bill to repeal and replace ... in May, the Senate bill would make significant cuts to Medicaid, a public ...
(Date:6/23/2017)... , ... June 23, 2017 , ... The Military Officers ... nominee for deputy secretary of Veterans Affairs, retired Marine Col. Thomas G. Bowman. , ... , Bowman brings an intimacy with the issues and challenges veterans face ...
(Date:6/23/2017)... ... 23, 2017 , ... Military Connection friend and veteran advocate Micaela ... Virgin Atlantic lounge. , Bensko is no stranger to the plight of the ... her life to supporting our wounded veterans. A world-class photographer, her riveting photos “The ...
(Date:6/23/2017)... ... June 23, 2017 , ... Goodcents Deli Fresh Subs today announced the opening ... 4210 SW 21st St. Topeka, Kan. 66604 (near 21st and Gage). It is owned ... owns three other locations in the Topeka and Bonner Springs, Kan. area. , ...
(Date:6/23/2017)... ... 2017 , ... Ensuring meat products have reached the proper ... of correctly using a meat thermometer. The videos feature University of California Davis ... food safety habits. Dr. Bruhn explains the variety of meat thermometers available on ...
Breaking Medicine News(10 mins):
(Date:6/1/2017)... , June 1, 2017 Nutriceutical Holdings ... Veterinarian Recommended Solutions (VRS), and KD Pharma Group have ... Nutriceutical Holdings by KD Pharma Group. KD Pharma Group ... the option to acquire the entire company. ... KD. They are committed to growing the NH companies ...
(Date:5/30/2017)... , May 30, 2017 Therapix Biosciences Ltd. ... specializing in the development of cannabinoid-based drugs, today ... company overview at three upcoming scientific and investor ... LD Micro Invitational: ... Date:                     ...
(Date:5/26/2017)... , May 25, 2017  In response to the ... , Direct Relief is working with Pfizer to make ... at no cost to community health centers, free and ... nationwide. "Pfizer has a long-standing commitment ... and ensuring patient safety through educational activities," said ...
Breaking Medicine Technology: