(Press-News.org) EVANSTON, Ill. --- It seems the old nature versus nurture debate can't be won. But a new Northwestern University study of men in the Philippines makes a strong case for nurture's role in male to female differences -- suggesting that rapid weight gain in the first six months of life predicts earlier puberty for boys.
Males who experienced rapid growth as babies -- an indication that they were not nutritionally stressed -- also were taller, had more muscle and were stronger, and had higher testosterone levels as young adults. They had sex for the first time at a younger age and were more likely to report having had sex in the past month, resulting in more lifetime sex partners.
The researchers think that testosterone may hold the key to understanding these long-term effects.
"Most people are unaware that male infants in the first six months of life produce testosterone at approximately the same level as an adult male," said Christopher W. Kuzawa, associate professor of anthropology in the Weinberg College of Arts and Sciences and author of the study. "We looked at weight gain during this particular window of early life development, because testosterone is very high at this age and helps shape the differences between males and females."
The study provides more evidence that genes alone do not shape our fate.
"The environment has a very strong hand in how we turn out," Kuzawa said. "And this study extends that idea to the realm of sex differences and male biology."
The study found men, on average, tend to be taller and more muscular than females, and the magnitude of that difference appears to be the result of nutrition within the first six months of an infant male's life, according to the study.
"There is a perennial question about how important heredity is versus the environment as shapers of who we turn out to be," said Kuzawa. "In the last 20 years, a lot has been learned about a process called developmental plasticity -- how the body responds early in life to things like nutrition and stress. Early experiences can have a permanent effect on how the body develops, and this effect can linger into adulthood. There is a lot of evidence that this can influence risk of diseases like heart attack, diabetes and hypertension -- really important diseases."
Kuzawa and his collaborators applied the same framework in this study and found evidence that male characteristics -- such as height, muscle mass and testosterone levels as opposed to disease characteristics -- also relate back to early life developmental plasticity.
"Another way to look at it is that the differences between the sexes are not hard wired, but are responsive to the environment, and in particular to nutrition," Kuzawa said.
Testosterone has long been known to increase muscle mass and puts a person on a higher growth trajectory to be taller. The Northwestern study suggests that the age of puberty also is influenced by events in the first six months of life.
The study, which was funded by the National Science Foundation and the Wenner Gren Foundation, was conducted among a group of 770 Filipino males aged 20 to 22 who have been followed their entire lives. Since 1983 a team of researchers in the United States and the Philippines (including Kuzawa for about the last 10 years) has been working to understand how early life nutrition influences adult health, such as risk for cardiovascular disease and diabetes.
"Rapid Weight Gain After Birth Predicts Life History and Reproductive Strategy in Filipino Males" was published Sept. 13 in the Proceedings of the National Academy of Sciences. The study's co-authors are Thomas W. McDade, associate professor of anthropology, Northwestern University, Linda S. Adair, University of North Carolina at Chapel Hill, and Nanette Lee, University of San Carlos of the Office of Population Studies in Cebu City, Philippines.
INFORMATION:
NORTHWESTERN NEWS: www.northwestern.edu/newscenter/
Male maturity shaped by early nutrition
Differences between the sexes affected by environment during first six months of life
2010-09-13
ELSE PRESS RELEASES FROM THIS DATE:
Manatee subspecies genetically confirmed, but diversity challenge looms
2010-09-13
Gainesville, FL. -- The first genetic study to compare nuclear DNA of endangered Antillean manatees in Belize with Florida manatees confirmed their designation as separate subspecies. Belize's manatees, however, were found to have extremely low genetic diversity, raising questions about their long-term genetic viability.
The Central American country of Belize hosts the largest known breeding population of Antillean manatees and is touted by biologists for its potential to repopulate other parts of Central America where manatees are severely reduced, rare or absent.
...
Information patients use to pick physicians not always good predictor of quality, study finds
2010-09-13
When looking for a new physician, patients are often encouraged to select those who are board certified or who have not made payments on malpractice claims. Yet these characteristics are not always a good predictor of which physicians will provide the highest quality medical care, according to a new study from the RAND Corporation, a nonprofit research organization, and the University of Pittsburgh School of Medicine.
"We found that the types of information widely available to patients for choosing a physician do not predict whether that physician will deliver evidence-based ...
Wildflower 'armors' itself against disease
2010-09-13
An unusual wildflower that accumulates metals in its leaves has been found to use them as a kind of 'armor' against bacterial infection. Scientists from Oxford University have shown that when Alpine pennycress (Thlaspi caerulescens) plants accumulate metals in their leaves, they become resistant to attack by the bacterium Pseudomonas syringae pv. maculicola. They report their findings September 9 in the open-access journal PLoS Pathogens.
Thlaspi, a small plant in the mustard family that grows on metal-rich soils scattered around Britain and Europe, such as the sites ...
New artificial skin could make prosthetic limbs and robots more sensitive
2010-09-13
VIDEO:
Artificial skin for people and robots could be a reality using the ultra-sensitive sensors developed by Zhenan Bao, associate professor of chemical engineering at Stanford University, and her team. The...
Click here for more information.
The light, tickling tread of a pesky fly landing on your face may strike most of us as one of the most aggravating of life's small annoyances. But for scientists working to develop pressure sensors for artificial skin for use on ...
Would a molecular horse trot, pace or glide across a surface?
2010-09-13
RIVERSIDE, Calif. – Molecular machines can be found everywhere in nature, for example, transporting proteins through cells and aiding metabolism. To develop artificial molecular machines, scientists need to understand the rules that govern mechanics at the molecular or nanometer scale (a nanometer is a billionth of a meter).
To address this challenge, a research team at the University of California, Riverside studied a class of molecular machines that 'walk' across a flat metal surface. They considered both bipedal machines that walk on two 'legs' and quadrupedal ones ...
New pathway identified in Parkinson's through brain imaging
2010-09-13
(NEW YORK, NY, September 13, 2010) – A new study led by researchers at Columbia University Medical Center has identified a novel molecular pathway underlying Parkinson's disease and points to existing drugs which may be able to slow progression of the disease.
The pathway involved proteins – known as polyamines – that were found to be responsible for the increase in build-up of other toxic proteins in neurons, which causes the neurons to malfunction and, eventually, die. Though high levels of polyamines have been found previously in patients with Parkinson's, the new ...
Wives as the new breadwinners
2010-09-13
Durham, NH—September 13, 2010— During the recent recession in the United States, many industries suffered significant layoffs, leaving individuals and families to revise their spending and rethink income opportunities. Many wives are increasingly becoming primary breadwinners or entering the labor market. A new article in Family Relations tests "the added worker" theory, which suggests wives who are not working may seek work as a substitute for husband's labor if he becomes unemployed, and finds that during a time of economic downturn wives are more likely to enter the ...
Making cookies that are good for your heart
2010-09-13
VIDEO:
Years of research has proven that saturated and trans fats clog arteries, make it tough for the heart to pump and are not valuable components of any diet. Unfortunately, they...
Click here for more information.
COLUMBIA, Mo. ¬— Years of research has proven that saturated and trans fats clog arteries, make it tough for the heart to pump and are not valuable components of any diet. Unfortunately, they are contained in many foods. Now, a University of Missouri research ...
Obama administration responds to call to action from Concordia researchers
2010-09-13
Montreal / September 13, 2010 – September 21, 2010 marks the one year anniversary of the release of a landmark document produced by researchers at Concordia University. Mobilizing The Will to Intervene (W2I) offers governments practical steps to prevent future genocides and mass atrocities. Produced by researchers with the Montreal Institute for Genocide and Human Rights Studies (MIGS) based at Concordia, the document was presented to the governments of Canada and The United States of America. It has already yielded concrete results.
Under President Barack Obama's leadership, ...
Latent HIV infection focus of NIDA's 2010 Avant-Garde Award
2010-09-13
The National Institute on Drug Abuse (NIDA), part of the National Institutes of Health, announced today that Dr. Eric M. Verdin of the J. David Gladstone Institutes in San Francisco, Calif., has been selected as the 2010 recipient of the NIDA Avant-Garde Award for HIV/AIDS Research for his proposal to study the mechanisms of latent HIV infection. NIDA's annual Avant-Garde award competition, now in its third year, is intended to stimulate high-impact research that may lead to groundbreaking opportunities for the prevention and treatment of HIV/AIDS in drug abusers. Awardees ...
LAST 30 PRESS RELEASES:
Reality check: making indoor smartphone-based augmented reality work
Overthinking what you said? It’s your ‘lizard brain’ talking to newer, advanced parts of your brain
Black men — including transit workers — are targets for aggression on public transportation, study shows
Troubling spike in severe pregnancy-related complications for all ages in Illinois
Alcohol use identified by UTHealth Houston researchers as most common predictor of escalated cannabis vaping among youths in Texas
Need a landing pad for helicopter parenting? Frame tasks as learning
New MUSC Hollings Cancer Center research shows how Golgi stress affects T-cells' tumor-fighting ability
#16to365: New resources for year-round activism to end gender-based violence and strengthen bodily autonomy for all
Earliest fish-trapping facility in Central America discovered in Maya lowlands
São Paulo to host School on Disordered Systems
New insights into sleep uncover key mechanisms related to cognitive function
USC announces strategic collaboration with Autobahn Labs to accelerate drug discovery
Detroit health professionals urge the community to act and address the dangers of antimicrobial resistance
3D-printing advance mitigates three defects simultaneously for failure-free metal parts
Ancient hot water on Mars points to habitable past: Curtin study
In Patagonia, more snow could protect glaciers from melt — but only if we curb greenhouse gas emissions soon
Simplicity is key to understanding and achieving goals
Caste differentiation in ants
Nutrition that aligns with guidelines during pregnancy may be associated with better infant growth outcomes, NIH study finds
New technology points to unexpected uses for snoRNA
Racial and ethnic variation in survival in early-onset colorectal cancer
Disparities by race and urbanicity in online health care facility reviews
Exploring factors affecting workers' acquisition of exercise habits using machine learning approaches
Nano-patterned copper oxide sensor for ultra-low hydrogen detection
Maintaining bridge safer; Digital sensing-based monitoring system
A novel approach for the composition design of high-entropy fluorite oxides with low thermal conductivity
A groundbreaking new approach to treating chronic abdominal pain
ECOG-ACRIN appoints seven researchers to scientific committee leadership positions
New model of neuronal circuit provides insight on eye movement
Cooking up a breakthrough: Penn engineers refine lipid nanoparticles for better mRNA therapies
[Press-News.org] Male maturity shaped by early nutritionDifferences between the sexes affected by environment during first six months of life