Random factoids; sleepy post

[kimberkit]

So, some random factoids from class, which I was reminded of over a lovely coffee with regyt earlier....

From my human development class: puberty in girls begins between ages 8-13 (link to about.com). That is wacky stuff if you think about how we must start sex education much earlier than we currently do -- I got mine in 6th grade, at age 11. That is actually three years too late to explain the question of, "Why is my chest tender and growing?" if you happen to be at the lower end of the developmental spectrum. It is also just odd to consider -- 8 seems so young and innocent. But... we have a case of a mother who gave birth when she was five years old.

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From my biology class: longevity is genetically related -- there are genes that code for aging. Unfortunately, if you have those genes activated, chances for cancer skyrocket. (This article seems to back up my bio teacher)

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From my physics class -- okay, more of a random thought: if light is an electromagnetic wave, and those converter-glasses from all the cool spy movies allow you to see infrared light, how much more sensitive can those conversion glasses get? Can they let you see radio waves? Holy moly, that would be spiffy.

Comments

[shellaby.livejournal.com]

I'm sure you've heard studies and statistics showing that the average onset of puberty is getting younger and younger, presumably because of hormones and chemicals in our food.

[g-me.livejournal.com]

I've read some things that posit that such early onset of puberty can be linked to high levels or certain hormones triggered from eating a lot of hormone-filled food products. In my own observation I've seen girls hit puberty as early as 10, but 8 seems to be the extreme...still, I fully support lifelong sex ed, starting as soon as kids have any questions, or maybe before.

[kimberkit.livejournal.com]

Possibly that, but it has been trending downwards since the 1830s in basically every Western country, while not all of those countries used genetically modified or hormonally enhanced food.

The most widely accepted theory (not the only theory, mind you, and it doesn't rule out the effect of increased hormones/ increased light exposure/ whatever other theory) is that we are better nourished and fatter. We need to accumulate a certain amount of fat in our bodies before our hypothalomus is signaled to produce the puberty-hormones, and it is easier to get that amount of fat now than it was a century or two ago.

[kimberkit.livejournal.com]

Yeah, the "hormone-filled food" thing is controversial -- I mean, on the one hand, countries in Europe tend to have a mean puberty age that is almost a year higher than that of the United States. In Europe, they don't tend to use genetically modified foods and are a little better with their meat raising, while we in the United States cheerfully threw such caution to the wind. On the other hand, we also:
(1) Have a more genetically diverse population, including an African-American population still averaging a relatively low socio-economic status (which means they eat fast food and fattening food).
(2) Have a fatter population, because we don't do portion control the way that most of Europe does. See comment to Shelley about fat and its link to triggering the hypothalomus' signal to start the puberty-cycle.

As for girls hitting puberty as early as 10, 10 is actually the mean age, not 8 (8 is still normal range, but the low end) -- but puberty is multi-staged, and having breast buds might happen a year before getting your first period.

[g-me.livejournal.com]

Interesting stuff.
I think, in terms of the hormones, I meant more extreme cases of some isolated populations I'd read about where girls experienced the onset of puberty at around age 6 due to some link to hormones in the stuff they were eating...I agree it's hard to isolate specific causal effects.

And I should have been more precise in my language about age for "hitting puberty." I think I actually meant that I've seen girls as young as 10 who were obviously well past the "hitting" stage.

[kimberkit.livejournal.com]

Holy crap. Any younger and we'll have toddlers experiencing puberty, and how traumatizing would that be?! [Actually, the mental image both makes me want to laugh and run away at the same time]