Featured Research

from universities, journals, and other organizations

Aggressive Behavior In Boys And Men May Not Be A Learned Behavior; Reduced Levels Of A Vascoconstrictor Triggers Physiological Processes Leading To Fighting, Biting, And Scratching

Date:
October 19, 2001
Source:
American Physiological Society
Summary:
Poets and writers of great literature may be disappointed to learn that the aggressive male passions that have caused duels, skirmishes, and wars are the result of reduced levels of serotonin in the brain. Why men? A group of researchers from the University of Akron state the Y chromosome that determines "maleness" (as opposed to the XX in females) governs serotonin levels. When stimulated, serotonin decreases, testosterone increases, and aggression results.

PITTSBURGH, Pa. -- Why do men fight? For centuries, philosophers have pondered this question. Some have suggested that aggressive behavior is part of the male make-up; others claim that fighting is a socially inspired behavior, a belief that has led to a wide range of child-rearing tactics.

Poets and writers of great literature may be disappointed to learn that the aggressive male passions that have caused duels, skirmishes, and wars are the result of reduced levels of serotonin in the brain. Why men? A group of researchers from the University of Akron state the Y chromosome that determines "maleness" (as opposed to the XX in females) governs serotonin levels. When stimulated, serotonin decreases, testosterone increases, and aggression results.

The authors of the study, "Sex Differences in Brain Monamines and Aggression," are Jonathon Toot, Gail Dunphry, and Daniel Ely, from the Department of Biology, The University of Akron, Akron, Ohio. Their findings are being presented in detail at the conference, Genomes and Hormones: An Integrative Approach to Gender Differences in Physiology, an American Physiological Society (APS) conference being held October 17-20, 2001, at the Westin Convention Center, Pittsburgh, Pa.

Methodology and Results

"Resident intruder" tests were used to measure the aggression and stress of male and female rats. In a colony of male and female rats a hierarchy is established, with male rats assuming a dominant role over the female rats.

Different male and female rats were then introduced into the established colony. Male intruders were attacked 2.6 times and received 1.8 scars over 15 minutes. Female intruders were not the perpetuators or recipients of any attack.

Norepinephrine, dopamine and serotonin were measured by high performance liquid chromatography (HPLC) in various regions of the brain including hypothalamus (VMH), media amygdala AME), lateral amygdala (ABL) and hippocampus (HPC). Norepinephrine content of VMH, AME, ABL, and HPC was not statistically different between the two sexes. However, values of dopamine in ABL of males were significantly less than corresponding female rats; levels of serotonin in the AME and ABL were also less in males compared to females.

Conclusion

In males, decreased serotonin in the amygdala was associated with increases in aggressive behavior. Whether this relates only to the presence of the Y chromosome or to a combination of the Y chromosome and male hormone testosterone, remains to be determined.

The American Physiological Society (APS) was founded in 1887 to foster basic and applied science, much of it relating to human health. The Bethesda, MD-based Society has more than 10,000 members and publishes 3,800 articles in its 14 peer-reviewed journals every year.


Story Source:

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


Cite This Page:

American Physiological Society. "Aggressive Behavior In Boys And Men May Not Be A Learned Behavior; Reduced Levels Of A Vascoconstrictor Triggers Physiological Processes Leading To Fighting, Biting, And Scratching." ScienceDaily. ScienceDaily, 19 October 2001. <www.sciencedaily.com/releases/2001/10/011019074815.htm>.
American Physiological Society. (2001, October 19). Aggressive Behavior In Boys And Men May Not Be A Learned Behavior; Reduced Levels Of A Vascoconstrictor Triggers Physiological Processes Leading To Fighting, Biting, And Scratching. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2001/10/011019074815.htm
American Physiological Society. "Aggressive Behavior In Boys And Men May Not Be A Learned Behavior; Reduced Levels Of A Vascoconstrictor Triggers Physiological Processes Leading To Fighting, Biting, And Scratching." ScienceDaily. www.sciencedaily.com/releases/2001/10/011019074815.htm (accessed September 20, 2014).

Share This



More Mind & Brain News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Food Addiction Might Be Caused By PTSD

Food Addiction Might Be Caused By PTSD

Newsy (Sep. 18, 2014) New research shows that women who suffer from PTSD are three times more likely to develop a food addiction. Video provided by Newsy
Powered by NewsLook.com
Corporal Punishment on Decline, Debate Renews

Corporal Punishment on Decline, Debate Renews

AP (Sep. 16, 2014) Corporal punishment in the United States is on the decline, but there is renewed debate over its use after Minnesota Vikings running back Adrian Peterson was charged with child abuse. (Sept. 16) Video provided by AP
Powered by NewsLook.com
FDA Eyes Skin Shocks Used at Mass. School

FDA Eyes Skin Shocks Used at Mass. School

AP (Sep. 15, 2014) The FDA is considering whether to ban devices used by the Judge Rotenberg Educational Center in Canton, Massachusetts, the only place in the country known to use electrical skin shocks as aversive conditioning for aggressive patients. (Sept. 15) 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