© Gray's Anatomy, 1918An illustration of a fetus in utero from Gray's Anatomy.
Researchers studied a group of boys ages 8 to 11 whose fetal testosterone had been measured from amniotic fluid when their mothers were 13-20 weeks pregnant.
Sex hormone levels, which increase during adolescence, are also heightened during critical periods of fetal brain development.
The boys in the study were shown pictures of negative (fearful), positive (happy), neutral, or scrambled faces while a functional magnetic resonance imaging (fMRI) machine tracked changes in their brain activity. In the boys who had higher levels of fetal testosterone, the brain's reward system was more responsive to positive, compared with negative, facial cues, the researchers found.
This suggests those boys have a greater proclivity for "approach-related behaviors," such as fun-seeking and impulsivity.
"This work highlights how testosterone in fetal development acts as a programming mechanism for shaping sensitivity of the brain's reward system later in life and for predicting later tendency to engage in approach-related behaviors," study researcher Michael Lombardo, of the University of Cambridge, said in a statement.
For males, such behaviors are often heightened in teenage years and are found in extremes in many psychiatric conditions, such as substance abuse, autism and even psychopathy, which tend to affect more men than women.
"These insights may be especially relevant to a number of neuropsychiatric conditions with skewed sex ratios and which affect approach-related behavior and the brain's reward system," Lombardo added. (Testosterone is present in low levels in females and the hormone substantially impacts sex differences between men and women.)
The study appears online this month in the journal Biological Psychiatry. John Krystal, editor of the journal, commented, "These remarkable data provide new evidence that hormonal exposures early in life can have lasting impact on brain function and behavior."
OK scientists. I see a contradiction in your work here.
You say:
"In the boys who had higher levels of fetal testosterone, the brain's reward system was more responsive to positive, compared with negative, facial cues, the researchers found. "
Sounds good, testosterone is the male sex hormone, which appears to then suggest males of that nature are more responsive to positive reinforcement rather than negative. So how does that then link with psychopathy and then impulsiveness? How do you get something that makes you LESS prone to negative feedback make you MORE prone to psychopathy and impulsiveness? Just seems contradictory to me. I see negativity as more psychopathic and impulsiveness than positivity.
I think you are trying to back up your feminist power appeal with scientific ideology. This is just another study which seek to demonize the male gender. Like the one about the "selfish gene" or the extinction of the Y chromosome.
They might as well say men are stupid because they have penises or a Y chromosome. Penises and testosterone both are intrinsic to males.
Scientists are still trying to prove there is no soul and everything mental is based on brain chemistry, so they team up with feminism the new religion to establish their chemical soup theory.
Western Science... when are you gonna cure cancer?