OK, Mind blown. I just read an article that say that homo sapiens brains have shrunk by 10% in the last 40,000 years.

[KidsHappen]

The reason this blows my mind is because I know that the reason it is more difficult for humans to give birth than other mammals is that our infants brains are larger in comparison to our pelvic outlet than other animals. 

So if our brains used to be 10% larger while our body size was roughly the same how did we birth those babies. The only logical way that I can think of is that we had a shorter gestation period but would that mean that the infants were even less developed at birth and therefore less likely to survive? I suppose another possibility is that only adult brains have shrunk but that infant brains remained the same. The article didn't specify.

Does anyone know?

I find stuff like this fascinating. 

 

Edited August 18, 2022 by KidsHappen
typo in title

[El...]

Interesting! I just fell down the Google rabbit hole about this.

It makes me laugh that several of the articles I saw seemed defensive about it... "Size has no relation to intelligence overall! We're just as smart as ever!" 😆 I mean, we sure hope so? 

One article was referring to the last 3000 years in particular, and a person quoted said perhaps people were outsourcing memory to writing things down in that time frame. Maybe we need to start memorizing epics again? 

Anyway. Interesting!

[maize]

I fell down a rabbit hole too, but regarding pelvises:

https://massivesci.com/articles/pelvis-birth-children-walking-human-apes-evolution/

[Lecka]

https://www.amazon.com/Lucy-Beginnings-Humankind-Donald-Johanson/dp/0671724991
 

I think this is the book I read….. I read a book that talked about this and I think it was this book about Lucy.  
 

There is another author I might be thinking of.  
 

Edit:  I might be thinking of Stephen Jay Gould but nothing jumped out at me on Amazon.  
 

Whatever book I read was so good!  I think it’s the first one I linked but I’m not sure.  Maybe someone else will know.  It was a famous book.  

Edited August 18, 2022 by Lecka

[Katy]

I suspect we used to be more intelligent at non-abstract survival skills, and less intelligent at the abstract memory & knowledge work that is the way we measure IQ today. 

I actually dislike modern IQ tests for this reason. There may be a question about choosing which answer fits the pattern. All four answers will be part of a pattern. The most mathematical/abstract answer is the “right” one. But IMO the person with visual answer is going to be much more likely to notice something in a survival or war situation and live.

The fact that you can study for an IQ test and change your score by learning to recognize abstract answers & patterns means it isn’t a true test of cognitive ability at all. 

I’m sure my dad would score lower than me on an IQ test. But the man survived multiple tours in Vietnam. He could see camouflaged animals three times as far away as I could, whether they were potential food sources or dangerous ones like poisonous snakes or alligators. He would notice things like a change in bird calls that meant a bobcat was near. He used to take us on walks just to point out some panther or bear tracks he found. 

Some of this, I am sure, was a matter of exposure. But I think some of it is innate, because I am much better at it than DH and I’m not sure I spent any more time in the woods as a kid than DH did. 

[GailV]

1 hour ago, Katy said:

 

I’m sure my dad would score lower than me on an IQ test. But the man survived multiple tours in Vietnam. He could see camouflaged animals three times as far away as I could, whether they were potential food sources or dangerous ones like poisonous snakes or alligators. He would notice things like a change in bird calls that meant a bobcat was near. He used to take us on walks just to point out some panther or bear tracks he found. 

Some of this, I am sure, was a matter of exposure. But I think some of it is innate, because I am much better at it than DH and I’m not sure I spent any more time in the woods as a kid than DH did. 

I wonder if that has something to do with some sort of variability in the number of information bits per second that our conscious minds bother to process, which is way way lower than the info bits per second that our senses take in. Our bodies take in millions of information bits per second and our brains arrange less than 100 per second into the story it wants to present to us as reality. If a person had a natural tendency to process more of a certain type of information it seems to me they'd have an advantage (in that narrow field) over someone whose brain just sort of said "nah, I'm just gonna make up stuff to fill in there" even if both people worked (via exposure and practice) to build up that ability.

Is that something that happens -- that there's natural variability in that?

Also, I possibly spend way too much time thinking about these things (perception vs reality), and am way too happy to disrupt the entire discussion about pelvic floors (which used to be what I thought about a lot because pelvic floors are fascinating) so I can natter on indefinitely about this. So I'll just shut up now. 

Except to say that a thread that has some of the diverse niche areas I obsess about all thrown in together? Woohoo, this is the stuff dreams are made of. 

[heartlikealion]

This is probably completely wrong but I did wonder if they meant shrunk in terms of how much we're using vs the actual space it takes up. Like less wrinkles or inactive parts. 

[Katy]

44 minutes ago, GailV said:

I wonder if that has something to do with some sort of variability in the number of information bits per second that our conscious minds bother to process, which is way way lower than the info bits per second that our senses take in. Our bodies take in millions of information bits per second and our brains arrange less than 100 per second into the story it wants to present to us as reality. If a person had a natural tendency to process more of a certain type of information it seems to me they'd have an advantage (in that narrow field) over someone whose brain just sort of said "nah, I'm just gonna make up stuff to fill in there" even if both people worked (via exposure and practice) to build up that ability.

Is that something that happens -- that there's natural variability in that?

Also, I possibly spend way too much time thinking about these things (perception vs reality), and am way too happy to disrupt the entire discussion about pelvic floors (which used to be what I thought about a lot because pelvic floors are fascinating) so I can natter on indefinitely about this. So I'll just shut up now. 

Except to say that a thread that has some of the diverse niche areas I obsess about all thrown in together? Woohoo, this is the stuff dreams are made of. 

I love this thread idea too! 

The other thing that’s interesting to me is the research that shows adult mental health decreases inversely to adventurous & dangerous childhood play. So basically we’ve padded playgrounds and removed tall jungle gyms and put safety rails everywhere so kids break less bones, but as they slide into adulthood they have worse mental health. It’s like being exposed to real physical danger as a child leaves adult brains better able to handle psychological stress. 

I have a friend who is a pastor now but for years she managed a large church daycare. She thinks that all formal academics should be delayed until at least age 7 for boys, and they should spend time “jumping off rocks in the woods” instead. I told her she should start a forest school. 

[stephanier.1765]

We definitely were pretty smart back then. We recognized fire as a heat source and to use it to cook food. We found ways to make it ourselves. We recognized the benefits of domesticating animals and to grow our own foods. Our minds conceived the wheel. We found ways to govern ourselves to help improve the lives of whole communities. We built pyramids, which totally blows my mind. We're still no dummies, by any means, but those early brains were pretty darn impressive.

[KidsHappen]

10 hours ago, maize said:

I fell down a rabbit hole too, but regarding pelvises:

https://massivesci.com/articles/pelvis-birth-children-walking-human-apes-evolution/

Well, this article had a picture that showed the comparison between infant brains and the pelvic outlet that referred to the last 200,000 years so perhaps the infant brains did in fact remain the same size at birth but reached different sizes in adulthood. That would be the  easiest answer.

[KidsHappen]

9 hours ago, Lecka said:

https://www.amazon.com/Lucy-Beginnings-Humankind-Donald-Johanson/dp/0671724991
 

I think this is the book I read….. I read a book that talked about this and I think it was this book about Lucy.  
 

There is another author I might be thinking of.  
 

Edit:  I might be thinking of Stephen Jay Gould but nothing jumped out at me on Amazon.  
 

Whatever book I read was so good!  I think it’s the first one I linked but I’m not sure.  Maybe someone else will know.  It was a famous book.  

I own a much older version of this book (like from when it was first published) and I remember loving it. I have not read it in a long time though so perhaps it is time for a reread. I have an entire shelf of books on human evolution alone.

[KidsHappen]

8 hours ago, GailV said:

I wonder if that has something to do with some sort of variability in the number of information bits per second that our conscious minds bother to process, which is way way lower than the info bits per second that our senses take in. Our bodies take in millions of information bits per second and our brains arrange less than 100 per second into the story it wants to present to us as reality. If a person had a natural tendency to process more of a certain type of information it seems to me they'd have an advantage (in that narrow field) over someone whose brain just sort of said "nah, I'm just gonna make up stuff to fill in there" even if both people worked (via exposure and practice) to build up that ability.

Is that something that happens -- that there's natural variability in that?

Also, I possibly spend way too much time thinking about these things (perception vs reality), and am way too happy to disrupt the entire discussion about pelvic floors (which used to be what I thought about a lot because pelvic floors are fascinating) so I can natter on indefinitely about this. So I'll just shut up now. 

Except to say that a thread that has some of the diverse niche areas I obsess about all thrown in together? Woohoo, this is the stuff dreams are made of. 

I do believe that there is a certain amount of natural variability in processing speeds of the human brain and that all brains may process things slightly differently which is especially obvious in cases of brain injury. 

[KidsHappen]

12 hours ago, elroisees said:

Interesting! I just fell down the Google rabbit hole about this.

It makes me laugh that several of the articles I saw seemed defensive about it... "Size has no relation to intelligence overall! We're just as smart as ever!" 😆 I mean, we sure hope so? 

One article was referring to the last 3000 years in particular, and a person quoted said perhaps people were outsourcing memory to writing things down in that time frame. Maybe we need to start memorizing epics again? 

Anyway. Interesting!

Another possibility is that the parts of the brain that shrank may not have been contributing that much but still using precious resources so that it was an advantage to downsize and become more efficient.

[KidsHappen]

8 hours ago, heartlikealion said:

This is probably completely wrong but I did wonder if they meant shrunk in terms of how much we're using vs the actual space it takes up. Like less wrinkles or inactive parts. 

The article seem to be stating that the overall size has gone down but like I said in another post perhaps it was a paring of less useful (or inactive) parts.

[KidsHappen]

9 hours ago, Katy said:

I suspect we used to be more intelligent at non-abstract survival skills, and less intelligent at the abstract memory & knowledge work that is the way we measure IQ today. 

I actually dislike modern IQ tests for this reason. There may be a question about choosing which answer fits the pattern. All four answers will be part of a pattern. The most mathematical/abstract answer is the “right” one. But IMO the person with visual answer is going to be much more likely to notice something in a survival or war situation and live.

The fact that you can study for an IQ test and change your score by learning to recognize abstract answers & patterns means it isn’t a true test of cognitive ability at all. 

I’m sure my dad would score lower than me on an IQ test. But the man survived multiple tours in Vietnam. He could see camouflaged animals three times as far away as I could, whether they were potential food sources or dangerous ones like poisonous snakes or alligators. He would notice things like a change in bird calls that meant a bobcat was near. He used to take us on walks just to point out some panther or bear tracks he found. 

Some of this, I am sure, was a matter of exposure. But I think some of it is innate, because I am much better at it than DH and I’m not sure I spent any more time in the woods as a kid than DH did. 

There has also been shown to be cultural bias built into the IQ test so we are not quite testing what we think we testing.

[KidsHappen]

7 hours ago, Katy said:

I love this thread idea too! 

The other thing that’s interesting to me is the research that shows adult mental health decreases inversely to adventurous & dangerous childhood play. So basically we’ve padded playgrounds and removed tall jungle gyms and put safety rails everywhere so kids break less bones, but as they slide into adulthood they have worse mental health. It’s like being exposed to real physical danger as a child leaves adult brains better able to handle psychological stress. 

I have a friend who is a pastor now but for years she managed a large church daycare. She thinks that all formal academics should be delayed until at least age 7 for boys, and they should spend time “jumping off rocks in the woods” instead. I told her she should start a forest school. 

I absolutely agree. My younger children started formal school a few years later than my older ones with some starting math and reading at 4 and other not until 7 or 8. The end results were about the same so grandchildren also started a little later as well except for one precocious student lead 3 year old.  

[Laura Corin]

On 8/18/2022 at 1:09 PM, maize said:

I fell down a rabbit hole too, but regarding pelvises:

https://massivesci.com/articles/pelvis-birth-children-walking-human-apes-evolution/

Fascinating.  I remember an OBGYN saying to me that the pelvis wasn't well designed for walking upright, and that prolapse was the consequence.  This is a much more interesting and nuanced view than that.

[ktgrok]

On 8/18/2022 at 8:09 AM, maize said:

I fell down a rabbit hole too, but regarding pelvises:

https://massivesci.com/articles/pelvis-birth-children-walking-human-apes-evolution/

Anyone else who gave birth to big babies looking at that chimpanzee pelvis with blatant jealousy??? Do they just sneeze and the kid comes out? Like, WOW!!! 

Never knew I could be this jealous of another animal's pelvis. 

[Katy]

3 hours ago, ktgrok said:

Anyone else who gave birth to big babies looking at that chimpanzee pelvis with blatant jealousy??? Do they just sneeze and the kid comes out? Like, WOW!!! 

Never knew I could be this jealous of another animal's pelvis. 

I didn’t have any big babies, but I’m jealous too!