[Puffer Fish]

Researchers find that children from poor families begin puberty sooner

https://www.weforum.org/agenda/2017/06/ ... ty-faster/

An interesting finding, and one that I have long suspected. When I saw this article, immediately my theory came to mind.

The researchers of course are assuming that something about being poor must accelerate the onset of puberty. But they don't seem to be considering the other possibility: that the two are correlated. There may be a tendency for the poorer segments of society to have genes that result in reproduction at earlier ages, and this would include sexual maturity.

This would correlated to, what is known in ecology/biology as r/R selection theory.

The idea being that different species, or population groups, will adapt their reproductive strategies in different directions, taking place under evolutionary pressure (natural selection). Some will invest heavily in their offspring to make sure they survive, while others will produce as many offspring as possible.

It appears that these researchers in the study did not adjust for the factor of race in their statistics. It would be interesting to see what the results of that would have been. I could be possible that most of the correlation they are seeing is due to race.

source: "Children in poverty hit puberty much earlier. This is why", World Economic Forum, Ying Sun - Associate Professor and Visiting Academic, Centre for Adolescent Health, Murdoch Childrens Research Institute, June 1, 2017



" Compared to white girls, African American girls experience more accelerated sexual maturation as assessed by several indicators of pubertal development, including age at first menses (Chumlea, 2003; Freedman et al., 2002; Herman Giddens et al., 1997; Wu, Mendola, & Buck, 2002) "

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6097246/

sources:
Chumlea WC, Schubert CM, Roche AF, Kulin HE, Lee PA, Himes JH, Sun SS. Age at menarche and racial comparisons in US girls. Pediatrics. 2003;111(1):110–113.
Herman Giddens ME, Slora EJ, Wasserman RC, Bourdony CJ, Bhapkar MV, Koch GG, Hasemeier CM. Secondary sexual characteristics and menses in young girls seen in office practice: A study from the pediatric research in office settings network. Pediatrics. 1997;99(4):505–512.
Relation of age at menarche to race, time period, and anthropometric dimensions: the Bogalusa Heart Study.
Freedman DS, Khan LK, Serdula MK, Dietz WH, Srinivasan SR, Berenson GS
Pediatrics. 2002 Oct; 110(4):e43.


I wonder if the r/K selection thing might be mostly psychological and cultural, rather than (or perhaps in addition to) actual observable physical developmental traits caused by genetics?

[Puffer Fish]

some excerpts from a long article:

When to have the talk now? Boys reaching puberty younger, study finds
The Globe and Mail, by Carly Weeks, October 23, 2012

It turns out that girls may not be the only ones who are developing early. According to new research, boys may be entering puberty at a younger age than they were a few decades ago.

A generation ago, 11 or 12 was considered the average age for boys and girls to go through the physiologic changes that accompany puberty. Now, the onset age appears to be shifting younger, with an increasing number of children going through puberty at 9 or 10.

Although the difference is only a year or two, it is a significant change that could have implications for development, behaviour and even long-term health. It also poses complex new challenges to parents, who face having "the talk" earlier than expected, and to children, who will be trying to navigate a confusing time at an earlier stage of their emotional and psychological development.

"I don't think most parents are really prepared for their sons to go into early puberty in Grade 5," said Dr. Dina Panagiotopoulos, a pediatric endocrinologist at B.C. Children's Hospital and a clinician scientist at the Child and Family Research Institute based in Vancouver.

Over the past few years, health experts debated whether the trend was confined to girls. In the 1990s, research emerged showing that girls were entering puberty earlier than they were in previous decades. Although the phenomenon is now widely accepted by the medical community, the discussion continues over the impact that earlier onset of puberty has on childhood development, behaviour and future health of girls.

Last weekend, the American Academy of Pediatrics published an important new study that provides, for the first time, highly credible scientific evidence that the same is true for boys.

The study, based on U.S. research, found that puberty among boys is starting six months to two years earlier than previously documented. Ethnic trends emerged as well: For white boys, the earliest stage of puberty is occurring at 10.14 years, while among Hispanic boys, the onset is at 10.4 years. Black boys showed the earliest average age of onset, at 9.14 years. Signs of the onset of puberty include genital and pubic-hair growth, as well as testicular enlargement.

The causes of the shift toward an earlier onset of puberty are unknown, but some contributing factors could include excess weight or endocrine-disrupting chemicals found in the environment, both which can interact with the body's hormones.

However, it is unclear whether those theories hold water. Excess fat and endocrine-disrupting chemicals can expose boys to greater amounts of estrogen, which should have the effect of delaying puberty, Panagiotopoulos said. In fact, some studies have found that excess body fat is linked to delayed puberty in boys.

Other factors, including genetics, nutrition, demographics and socio-economic background, all probably play some role determining the onset of puberty. More research is needed to confirm whether pubertal onset is skewing younger in Canada and, if it is, to determine what is causing it and what impact it may have on future development.

The best advice for parents, according to experts, is to start a discussion about puberty and the changes that come with it before it happens. "Parents need to talk to kids about what's happening," said Dr. Debra Counts, an associate professor of pediatrics and division head for pediatric endocrinology at the University of Maryland School of Medicine.

"I think it can be challenging for boys," Panagiotopoulos said. "They might be growing taller and looking a little bit more mature, but their brain isn't quite ready for those changes and they're not psychologically ready to handle them."

Schools should also be ready to adapt and accept that changing behaviour in nine- and 10-year-old boys, such as increased aggression, could be a sign of early puberty onset, not a behavioural problem, pediatric health experts say. "I think that's where everyone needs to be aware," Panagiotopoulos said.

It's unclear what, if any, long-term health consequences may be linked to an early onset of puberty in boys. That is one area researchers will need to focus on as they work to better understand this trend.​

https://www.theglobeandmail.com/life/he ... le4632786/