cricket

This is from the Post of the Month at Talk Origins for July 2002

14-15 years = a generation?

Does this seem about right, to you?

Wouldn't it be calculated based on the average age of parents? Some of which would be in their thirties, even back then. Admittedly, most didn't live to be thirtysomething, but some did. Wouldn't their continued childbearing mean that a generation would be more than 14-15 years "on average"?

The Lone Ranger

That doesn't quite seem right, somehow.

It's my understanding that throughout most of the history of our species, few 14 year-old females would have been capable of successful reproduction. It's only in modern societies like ours (in which most people are healthier and much better-fed than our ancestors) that 14-year-olds are menstruating.

17 - 20 years seems more likely to me as an average generation time, and that's probably a bit on the low side.

If you go to old graveyards (200+ years old), you see an interesting phenomenon. Lots of women died at about 17-19 years of age. Not coincidentally, this is about the time that they gave birth to their first children. Up until recently, complications from childbirth was the leading cause of death among young women.

Cheers,

Michael

Bubba

Pardon this post from a thiest please but I'm not sure that your ages are correct.

My good friend John has done short term medical missions work in rural Kenya, Belize, several countries in Sourth America, etc.

His wife Sandy is a nurse. They have told me that it is very common for girls 13-16 to be getting married in some places they have worked.

Perhaps Scigirl, being female and in med school could enlighten us.

Chris

P.S. Yes, I realize there is a huge difference in diet between what your rural African child eats and what people ate 130,000 years ago.

Valentine Pontifex

I might point out that our pre-human ancestors were not, well, human. And that our nearest non-human relatives living today do not live nearly as long as humans do today.

And some paleoanthropologists think that Turkana Boy is evidence that Homo ergaster (Homo erectus to the lumpers) matured faster than humans do today.

scigirl

Sorry we don't learn anything that interesting...

scigirl

Bubba

This makes sense to me.

Chris

cricket

The TalkOrigins post was referring to our ancestors approx. 13,000 BC. They were h. sapiens, not homo erectus!

cricket

Yes but how is a generation measured? These girls are still bearing children 5, 10, 20 years later if they and their mates are alive that long. Not all are, especially not many in 13,000 BC, but some survived to bear children in their twenties & thirties, and that should drive the average up to 18-20.

Even if the commonest age for babies' parents was 15, the average age for babies' parents would have been higher. Because many parents would have been, for example, 10-15 years older than this (ages 25-30) but none would have been 10-15 years younger (ages 0-5). So the average would be higher than 15.

Surely an "average generation" is not calculated by the fastest possible way to do it, but by the average.

The TalkOrigins post says

This ancestor was not necessarily a first-born. Even if his mother began bearing children at 14 that doesn't mean he was born to a 14-year old. It's even less likely his father was 14 (might have been, but the average age of babies' fathers would surely be older.)

The same is true for our ancestors of any generation for the past several thousand years. The earliest-it-could-have-done age is different than the average age of each of our ancestor's parents.

Jan Haugland

It fits with everything I know about the subject.

Even today, the typical age for marriage for women is 13 in some primitive societies. It is a reasonable assumption that all through history, women were married off and started having children very soon after reaching childbearing age, ie. first menstruation.

Clarifying: It is of course true that this is the age of the first child, not the average age of the mother for every childbirth.


- Jan

...who rants and raves every day at Secular Blasphemy

Celsus

Hi all,

Sorry, this may end up as a rant. It probably also won't answer any questions, but someone may find this interesting. My research (not primary research, unfortunately) in Ghana always pointed to early marriage, fear of rape and kidnap, etc. as primary factors why girls were pulled out of primary school by parents. Marriage or first sexual contact was easily before the age of 15 in most cases.

From what I know of anthropological studies, marriage ages are very young. In the 1990 Census in Papua New Guinea, 20% of girls were married by the age of 15, and 80% by the age of 25. One anthropological study (although I forget the title) of the !Kung in Namibia (think the tribesmen in The Gods Must be Crazy) indicated they were sexually active by the age of 12-13, and married within a year of becoming active. They became active first so that they were allowed to experiment, including homosexually.

In Ethiopia, girls are married as early as 8, and it is common for their parents to pull them out of primary school for fear of pregnancy. Worse still, there have been experiences of parents kidnapping young primary school girls for "marriage" to their sons, yet another reason for parents to pull their daughters out of schools.

And of course, once they hit puberty, or possibly before, marriages are consummated. Here's the most disgusting rationalisation I ever heard:

Damn right "Religion explains why many female children are not going to school"! I witnessed exactly this sort of thing the two times I was in Niger (in their case, Muslims), and heard Ghanaians say the same thing quite unapologetically as well.

/rant

Joel

All quotes from Pauline Rose & Mercy Tembon, "Girls and Schooling in Ethiopia" in Christine Heward and Sheila Bunwaree (eds.), 1999, Gender, Education and Development: Beyond Access to Empowerment, London: Zed Books.

Edited to remove expletives.