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.

Related Articles


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 April 20, 2015 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 April 20, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Monday, April 20, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Our Love Of Puppy Dog Eyes Explained By Science

Our Love Of Puppy Dog Eyes Explained By Science

Newsy (Apr. 17, 2015) Researchers found a spike in oxytocin occurs in both humans and dogs when they gaze into each other&apos;s eyes. Video provided by Newsy
Powered by NewsLook.com
Scientists Find Link Between Gestational Diabetes And Autism

Scientists Find Link Between Gestational Diabetes And Autism

Newsy (Apr. 17, 2015) Researchers who analyzed data from over 300,000 kids and their mothers say they&apos;ve found a link between gestational diabetes and autism. Video provided by Newsy
Powered by NewsLook.com
Video Messages Help Reassure Dementia Patients

Video Messages Help Reassure Dementia Patients

AP (Apr. 17, 2015) Family members are prerecording messages as part of a unique pilot program at the Hebrew Home in New York. The videos are trying to help victims of Alzheimer&apos;s disease and other forms of dementia break through the morning fog of forgetfulness. (April 17) Video provided by AP
Powered by NewsLook.com
Common Pain Reliever Might Dull Your Emotions

Common Pain Reliever Might Dull Your Emotions

Newsy (Apr. 16, 2015) Each week, millions of Americans take acetaminophen to dull minor aches and pains. Now researchers say it might blunt life&apos;s highs and lows, too. Video provided by Newsy
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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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