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:2/12/2016)... ... February 12, 2016 , ... Miami Dental Specialists is ... to their Miami dental office. Beginning in January, Miami Dental Specialists will offer the ... Specialists are the first office to be chosen by the dental implant manufacturer, Straumann, ...
(Date:2/12/2016)... ... February 12, 2016 , ... ... surrounding communities by continuing it’s commitment to act as Agents of Change in ... works closely with area homeless families to fulfill immediate needs and help them ...
(Date:2/12/2016)... ... 12, 2016 , ... Nearly every health website and vision ... articles generally list between five and 15 foods that should be consumed regularly ... of these lists and believes that nutritious eye healthy foods are extremely important, ...
(Date:2/12/2016)... ... February 12, 2016 , ... Homeowners now have a ... CertainTeed, North America’s leading brand of building products, has improved upon its industry-best ... the mobile version of the ColorView® Exterior Style and Color Selector. Created expressly ...
(Date:2/12/2016)... Ranch, Colo. (PRWEB) , ... February 12, 2016 , ... ... over the past 35 years. A president has access to health and wellness resources ... of the free world, no single individual has a schedule as frenetic as the ...
Breaking Medicine News(10 mins):
(Date:2/12/2016)... , Feb. 12, 2016  Apellis ... completed a $47.1 million Series D preferred ... Asset Management, Hillhouse Capital Group and venBio ... Venture Investments, AJU IB Investment, and Epidarex ... used to further advance clinical trials in ...
(Date:2/11/2016)... -- The primary goal of this research is to ... usage of liquid biopsy. Key information the survey seeks ... of liquid biopsy adoption amidst future users - Predominantly ... - Sample inflow to conduct liquid biopsy tests - ... so on. - Correlation analysis of sample type and ...
(Date:2/11/2016)... SAN FRANCISCO , Feb. 11, 2016  Kindred ... focused on saving and improving the lives of pets, ... Technical Section of the New Animal Drug Application (NADA) ... the pivotal field study (KB0120) of Zimeta for the ... by the Company. --> ...
Breaking Medicine Technology: