Featured Research

from universities, journals, and other organizations

'Warrior Gene' Predicts Aggressive Behavior After Provocation

Date:
January 23, 2009
Source:
Brown University
Summary:
People with the so-called "warrior gene" exhibit higher levels of behavioral aggression in response to provocation, according to new research. In the experiment, subjects penalized opponents by administering varying amounts of hot sauce.

Individuals with the so-called "warrior gene" display higher levels of aggression in response to provocation.
Credit: iStockphoto/Viorika Prikhodko

Individuals with the so-called “warrior gene” display higher levels of aggression in response to provocation, according to new research co-authored by Rose McDermott, professor of political science at Brown University. In the experiment, which is the first to examine abehavioral measure of aggression in response to provocation, subjects were asked to cause physical pain to an opponent they believed had taken money from them by administering varying amounts of hot sauce.

The findings are published in the Proceedings of the National Academy of Sciences. In addition to McDermott, the research team included Dustin Tingley of Princeton University, Jonathan Cowden of the University of California–Santa Barbara, Giovanni Frazetto from the London School of Economics, and Dominic Johnson from the University of Edinburgh. Their experiment synthesized work in psychology and behavioral economics.

Monoamine oxidase A is an enzyme that breaks down important neurotransmitters in the brain, including dopamine, norepinephrine, and serotonin. The enzyme is regulated by monoamine oxidase A gene (MAOA). Humans have various forms of the gene,resulting in different levels of enzymatic activity. People with thelow-activity form (MAOA-L) produce less of the enzyme, while the high-activity form (MAOA-H) produces more of the enzyme.

Several studies have found a correlation between the low-activity form of MAOA and aggression in observational and survey-based studies. Only about a third of people in Western populations have the low-activity form of MAOA. By comparison, low-activity MAOA has been reported to be much more frequent (approaching two-thirds of people) in some populations that had a history of warfare. This led to a controversy over MAOA being dubbed the “warrior gene.”

The PNAS paper is the first experimental test of whether MAOA-L individuals display higher levels of actual behavioral aggression in response to provocation. A total of 78 subjects took part in the experiment over networked computers (all were male students from the University of California–Santa Barbara). Each subject (A) first performed a vocabulary task in which they earned money. Then they were told that an anonymous partner (B), linked over the network, could choose to take some of their earnings away from them. The original subject (A) could then choose to punish the taker (B) by forcing them to eat unpleasantly hot (spicy) sauce — but they had to pay to do so, so administering punishment was costly. In reality, the “partner” who took money away was a computer, which allowed the researchers to control responses. No one actually ingested hot sauce.

Their results demonstrate that

  • Low-activity MAOA subjects displayed slightly higher levels of aggression overall than high-activity MAOA subjects.
  • There was strong evidence for a gene-by-environment interaction, such that MAOA is less associated with the occurrence of aggression in the low-provocation condition (when the amount of money taken was low), but significantly predicted aggression in a high-provocation situation (when the amount of money taken was high).

The results support previous research suggesting that MAOA influences aggressive behavior, with potentially important implications for interpersonal aggression, violence, political decision-making, and crime. The finding of genetic influences on aggression and punishment behavior also questions the recently proposed idea that humans are “altruistic” punishers, who willingly punish free-riders for the good of the group. These results support theories of cooperation that propose there are mixed strategies in the population. Some people may punish more than others, and there may be an underlying evolutionary logic for doing so.


Story Source:

The above story is based on materials provided by Brown University. Note: Materials may be edited for content and length.


Cite This Page:

Brown University. "'Warrior Gene' Predicts Aggressive Behavior After Provocation." ScienceDaily. ScienceDaily, 23 January 2009. <www.sciencedaily.com/releases/2009/01/090121093343.htm>.
Brown University. (2009, January 23). 'Warrior Gene' Predicts Aggressive Behavior After Provocation. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2009/01/090121093343.htm
Brown University. "'Warrior Gene' Predicts Aggressive Behavior After Provocation." ScienceDaily. www.sciencedaily.com/releases/2009/01/090121093343.htm (accessed September 17, 2014).

Share This



More Health & Medicine News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com
Obama Orders Military Response to Ebola

Obama Orders Military Response to Ebola

AP (Sep. 16, 2014) Calling the Ebola outbreak in West Africa a potential threat to global security, President Barack Obama is ordering 3,000 U.S. military personnel to the stricken region amid worries that the outbreak is spiraling out of control. (Sept. 16) Video provided by AP
Powered by NewsLook.com
UN: 20,000 Could Be Infected With Ebola by Year End

UN: 20,000 Could Be Infected With Ebola by Year End

AFP (Sep. 16, 2014) Nearly $1.0 billion dollars is needed to fight the Ebola outbreak raging in west Africa, the United Nations say, warning that 20,000 could be infected by year end. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Obama: Ebola Outbreak Threat to Global Security

Obama: Ebola Outbreak Threat to Global Security

AP (Sep. 16, 2014) President Obama is ordering U.S. military personnel to West Africa to deal with the Ebola outbreak, which is he calls a potential threat to global security. (Sept. 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins