Help! And, social anthropology intersects vaccination debates

[velvetpage]

Wikipedia is failing me, as is google at the moment, and I've had a request to explain a certain term I used a day or so ago in a community.

The term I used is "grandparent factor," though I'm not sure that's the term anthropologists use for the situation I'm thinking of. When I learned about it in anthropology years ago, it was an explanation for menopause, which traditionally happens in middle age; that is, humans become effectively infertile several decades before the end of their expected lifespan. We're the only members of the animal kingdom that experience a loss of fertility so early, so anthropologists proposed that it might be due to the grandparent factor. Less-able elderly people stayed home from the hard work of hunting and gathering, and looked after the small children who were not yet old enough to participate in that hard work, thus freeing up the parents to contribute their strength and youth to the family and community. The explanation posits that menopause is nature's way of creating an available pool of babysitters within the family, people who would have a vested interest in seeing that the children of their lineage were being cared for.

This came up in a discussion of shingles. I just found out (from doc_mystery - it's no end of useful having doctors on one's friends list!) that shingles is not a new infection; it's the chicken-pox virus that has been hiding out in your nervous system ever since you had chicken pox as a child, and it erupts when your immune system is somehow suppressed. The interesting part is that regular exposure to chicken pox during adulthood seems to act as a booster shot, making it less likely that the person will eventually get shingles because their body will be able to fight better, even with a depressed immune system. I see a connection there. Older people who look after young kids are going to come into regular contact with chicken pox, all things being equal, so they're going to get an additional boost to their immune systems every few years. The grandparent factor offers an increase to natural immunity from shingles.

Anyone have any links to prove I'm not pulling this out of thin air?

Comments

Is it the Grandmother Hypothesis?

[used_songs]

http://www.nytimes.com/specials/women/warchive/970916_2115.html
http://en.wikipedia.org/wiki/Grandmother_hypothesis

Re: Is it the Grandmother Hypothesis?

[velvetpage.livejournal.com]

Yep, that's it! Thanks!

[beetiger.livejournal.com]

That's one of my big worries with the chicken-pox vaccine, actually. (And I'm generally pro-vaccine.) It's not ridiculous at all to think that blocking chicken pox as a childhood disease will cause an increase in shingles, which is a much more serious disease.

[velvetpage.livejournal.com]

But regular booster shots should eliminate that worry as far as it can be eliminated, thus reducing the toll of the disease overall.

[integritysinger.livejournal.com]

I don't have proof. But I'm wondering, for the sake of further discussion, how this grandparent factor has evolved with industrialization. Most grandparents I know DON'T raise their grandkids. In fact, the general consensus seems to be a disdain for their wayward parents that need help raising their children rather than being willing to lend a helping hand. the baby boomers that are approaching retirement age seem more concerned with their retirement pleasures than with their grandkids. (none of this is documented, BTW, just observation of our community, my family and the social circles I travel in). Perhaps this is more of a regional thing and not a generalized progression of civilization? Clearly the concept you state is more probable in the greater global populace where materialism is more important than familial duties.

[velvetpage.livejournal.com]

Yes, the theory is that menopause developed in hunter-gatherer societies, and allowed for a level of expansion that wasn't possible when the society had to stay in places where small children could find enough to eat. It's a survival mechanism for the group as a whole. Like many other things, industrialization has changed it, by making it less likely that grandparents will want to/be able to take on that role.

The link further up the thread talks about it in a lot more detail.

[(Anonymous)]

huh. that is interesting. I'm thinking of Sarah, Abraham's wife from the book of Genesis. At 90+ she laughs at abraham when he tells her that God has promised she will conceive. She says she is past her time or child bearing but concieves anyway.

So the question is, just when did true menopause start? Eve of course, concieved indefinitely. Scripture records that she and Adam lived into the 700's I think and that they bore children for a good portion of that time.

Similarly, Noah is presumed to have gone on to have more children with his wife after the flood and he was 200ish I think?

The time line would be that Abraham and Sarah were several hundred years after Noah and it is the first mention of the cessation of fertility.

I don't know if you subscribe to the historical content of the Bible or not but regardless, it is compelling within the context of the theory of the evolution of late-life infertility to aide in rearing the younger generations while the able bodied adults worked/hunted

[integritysinger.livejournal.com]

that was me BTW. forgot to login

[velvetpage.livejournal.com]

I figured that. :) Answer is up to the original comment, but you won't get it to your email since you weren't logged in.

[dornbeast.livejournal.com]

Similarly, Noah is presumed to have gone on to have more children with his wife after the flood and he was 200ish I think?

As I recall, age is not as strong a barrier to fatherhood as it is to motherhood. It is still a factor, but (exaggerating a bit) the chance of fertilizing an egg doesn't approach zero until the heart rate does.

[velvetpage.livejournal.com]

I don't believe those ages, or necessarily those people, were historically accurate - I believe they're myths told to justify elements of early civilizations on which Judaism is built, so I wouldn't look to those scriptures for that evidence. I would use them for the anthropology of cultural myth, but that's a different topic. :)

[catarzyna.livejournal.com]

I have a handout that I give my students on this. Would you like me to email it to you? It is a pdf file.

[velvetpage.livejournal.com]

Yes, that would be wonderful!

[mrs-dm.livejournal.com]

I've heard of the grandmother factor too. It makes sense, until you realize that for most of human history, people didn't live much past the age of menopause, so how could they have contributed much to the family?

Perhaps the more relevant factor is that fertility slowed down considerably by age 40, so prehistoric grandmas had a good 10 or 15 years to help out, even though they theoretically could have conceived (had they access to the kind of reproductive technologies that we have now).

[velvetpage.livejournal.com]

I'm not sure that's true. There are a few watershed moments in human life expectancy, and if you pass them, you've likely got a while to go before the next one. The first is birth, obviously, and the second is the first year, then the fifth. But a child who survived to the age of five had a pretty good chance of living long enough to reproduce. For a woman, the next moment would be childbirth, and again, if she survived it once, her chances of surviving it in the future were better. And once she got past the most fertile years, ill health would start to take its toll in her forties or fifties - but I'm sure there were many women even then who lived into their sixties or seventies. Not as high a percentage as now, obviously, but if the "average" lifespan ended between forty and fifty, that would mean about half survived longer than that.

Remember that one of the blessings in the Bible is, "May you live to see your children's children," and a man's days upon the earth were numbered at threescore and ten.

[mrs-dm.livejournal.com]

Yeah, the "average" lifespan thing has bothered me too. I guess it really depended on what kind of culture one was in. And lets not forget infectious diseases, which trumped just about any other cause of death for millenia, at least since densely populated towns/cities have existed.

I suppose if one really researched the anthropological literature, one could find the answer (I however, am too lazy!)

The Bible blessing could still be interpereted as meaning, "Well, if you're really lucky you can live to see 70, but that's pretty rare, boy!"

These days, the theoretical biological age limit is about 125 years. Ask doc_mystery sometime about theories of longevity. It's pretty interesting stuff.