MONTREAL Boys will be boys, as the adage goes, with their boisterous rough-and-tumble play so stereotypically male.
Is it the doings of a primary sex hormone called testosterone, long associated with social dominance, masculinity and strength?
Many scientists have explored the role of hormones and conduct, whether in school playgrounds, sports, war or bedrooms.
Now a Universite de Montreal study of five-month-old twins is among the first to tease out the contribution of genetic and environmental factors to circulating levels of this chemical.
The research with infant twins suggests that the environment plays a more significant role than genes when it comes to testosterone levels.
Studies in human and animal models over the past 50 years have confirmed an association between aggression, dominance, and testosterone in adolescence said lead author Richard Tremblay of UdeM’s research unit on children’s psychosocial maladjustment.
“The question is, when does that association start” asked Tremblay, whose team looked at newborn babies of both sexes.
Published in the online edition of Psychoneuroendocrinology, the study compared testosterone in saliva samples from a total of 314 infants identical twins with non-identical twins. Identical pairs share the same genes, while fraternal twins are like any siblings and share 50 percent of their genes.
“So if testosterone levels are genetically determined, then the identical twins would be more alike than the fraternal twins,” Tremblay explained.
Researchers found that testosterone levels in infancy are not inherited genetically but instead are affected by environmental factors.
Contact Us Now
- Acidosis: The Hidden Health Destroyer - December 12th, 2017
- Your Life on Testosterone: Overly Sure, Unwilling to Listen to Anyone - February 18th, 2017
- With testosterone, it's 'my way or the highway': UK study - Testosterone Prescription - February 11th, 2017
- Too much testosterone makes for bad decisions, tests show - Testosterone Prescription - February 4th, 2017
- The Secret to Guys’ Sex Appeal: Low Stress, High Testosterone, Strong Immunity - Testosterone Prescription - January 28th, 2017
- Testosterone, Viagra not a winning combination for erectile dysfunction - Testosterone Prescription - January 21st, 2017
- Testosterone therapy — good idea or not? - Testosterone Prescription - January 14th, 2017
- Testosterone shown to help sexually frustrated women- Testosterone Prescription - January 7th, 2017
- Testosterone replacement therapy improves symptoms of metabolic syndrome - Testosterone Prescription - December 31st, 2016
- Testosterone reduces group think, cooperation, and less sheep-like mentality - December 24th, 2016
- Testosterone linked to heart disease - Testosterone Prescription - December 17th, 2016
- Testosterone drives ego, helps eliminate group think - Testosterone Prescription - December 10th, 2016
- Men with higher testosterone tend to lie less, study suggests - December 3rd, 2016
- Low testosterone levels cause health woes - Testosterone Prescription - November 26th, 2016
- Increase in testosterone drug use - Testosterone Prescription - November 19th, 2016
- Five Myths About Low Testosterone And Testosterone Therapy - Testosterone Prescription - November 12th, 2016
- Dr Manny: Want to boost your testosterone? Try getting married - Testosterone Prescription - October 29th, 2016
- Co-sleeping with baby drops men’s testosterone levels - October 22nd, 2016
- The top ten testosterone booster supplements: A review - October 8th, 2016
- Hypogonadism Testosterone Archives - Testosterone Prescription - October 1st, 2016