Monday, August 16, 2010

The Shrinking Brain, Yeridos Hadoros (Dumbing Down Through the Generations), and Aggressiveness

Over Shabbos I saw this great article in Discovery Magazine (September 2010 Issue). It was "The Incredible Shrinking Brain" written by Kathleen McAuliffe. I was absolutely shocked by the consensus of scientists, the human brain has been shrinking for the past 10,000-20,000 years (From 1500 cc to 1350 cc, the size of a tennis ball). That seems to be counter to evolution and the idea that man has been getting smarter. However, as with all things in life, there are differing opinions as to what this means. (Just for clarity, the article says that the human brain grew bigger and bigger over the past 2 million years. Only recently has it begun to shrunk. This is not a counter evolution post.)

The first opinion brought down in the article is the "Dumbing Down theory." David Geary, a cognitive scientist of the University of Missouri said, "The best explanation for the decline in our brain size is the idiocracy theory." He is referring to a film made by Mike Judge in 2006 where the story line is that "Private Joe Bauers, the definition of 'average American', is selected by the Pentagon to be the guinea pig for a top-secret hibernation program. Forgotten, he awakes 500 years in the future. He discovers a society so incredibly dumbed-down that he's easily the most intelligent person alive." Geary and a colleague of his, Drew bailey, conducted experiments to back up this idea, but I won't bore you with the details.

The next idea is the polar opposite, that this brain shrinkage means we are getting smarter (which seems counter intuitive to me). This idea is present by the Anthropologist named Hawks. He performed research similar to Geary and Bailey and came up with the same exact data. In fact, he shows a large change between the Bronze Age and Medieval times. However, he interprets the data completely differently. Bailey and Geary just focus on the size decrease and say that it shows we have decreased our intelligence based on size. However, Hawks says that the decrease in size is in order to make the brain more efficient. A brain that is smaller, but gets the most output for the least amount of energy is the best possible brain and this is how our brains have changed.

There is a third school of thought that does not even relate this change to intelligence, but rather aggressiveness. According to a primatologist at Harvard University, Richard Wrangham, the same thing that has happened to domesticated animals has happened to humans. Domesticated animals have a 10%-15% reduction in brain volume compared to their wild progenitors. Wrangham says that this same trend has happened in humans. The easiest explanation is that, as Wrangham says, "Over the last 100,000 years, language became sufficiently sophisticated that when you had some bully who was a repeat offender, people got together and said 'We've got to do something about Joe (the bully).' And they would make a calm deliberate decision to kill Joe or expel him from the group." This would lead to natural selection weeding out aggressive traits and favoring those that are more calm and amicable. (He goes into a whole explanation as to why a less aggressive brain is smaller, if you want to read the whole science behind it get the magazine.)

Another shocking realization in this article comes at the end, the human brain has started to increase in size again. This finding was discovered by Richard Jantz, an anthropologist of the University of Tennessee. Hawks says this finding is most probably due to nutrition, since food today is much more abundant. Jantz and other scientists say that, based on their research (IQ tests), it seems like the brain size does correlate with intelligence.

Christopher Stringer, a paleontologist and expert on human origins at the Natural History Museum in London says the closing statement for the article, "It's perfectly plausible our modern brain is smarter in some ways, dumber in others and more docile overall."

I found this article absolutely fascinating for several reasons. Obviously, I think science is remarkable and the new information scientists of every field discover has a "Wow" factor for me. However, it is not every day that I come across an article that helps me understand ideas in Judaism in a new light. People always claim Yeridos Hadoros (Dumbing Down of the Generations) means that people get dumber and dumber as the years go by. At first, anyone who thinks evolution is probable (most people that think science makes sense) would write this off and say that evolution completely contradicts this. However, this article shows the EXACT OPPOSITE. Well, depending on which opinion we are going to give the most credence. However, the opinion that seems to make the most sense to me is that of Christopher Stringer, the last statement in the article. A shrinking brain can mean so many different things and it seems like a combination of all three changes (less intelligent in some areas, more intelligent in others and more docile) seems to be the most reasonable.

In light of this, it makes sense to say that Yeridos Hadoros could be that we have become less intelligent in certain areas and that is why halacha can not be argued on. However, hashkafa and science found in the ancient texts are not obligatory for this very reason (unless they are explicitly stated by G-D). An example as to why halacha would not be allowed to change, but hashkafa could is that halacha is based on memory. One must remember what Moshe said on Sinai and apply that ruling to a case. Hashkafa, on the other hand, is completely based on abstract thinking (Metaphysics is clearly abstract thinking. The beginning of the Universe and so on.) Perhaps we have been getting smarter in abstract thinking, but our memories are not as good (I mean, Einstein and others).

Also, the docile idea, we were more aggressive as a species in the past. Maybe this is why laws have changed in the way that they have. Also, perhaps this is why there are commandments in the Torah, from 3500 years ago, that make some people uncomfortable today (like killing Amalek). Back then it was necessary for the survival of a group to destroy their enemies, because that is how humans survived. However, today many groups (not all) are much more civilized and docile. The Torah was given 3500 years ago and needed to be able to relate to all times, especially at the time it was given. G-D knew that Amalek would not exist in the future, so maybe that is why He commanded them to be wiped out back then, because what was human nature back then is not what human nature is today (as shown in this article, the brain is smaller and more docile).

I don't know, but these are all possibilities. Only G-D really knows why everything is and how things have progressed. All we can do is guess and see if we are right.


Anonymous said...

Perhaps this can be viewed differently. The war against Amalek is to be waged at all times--until we win it, please G-d help us. The Torah tells us that Ishmael has not changed over time and Amalek has not changed in his objective over time, either. Since ours is a battle for survival, it seems that one of the effects of this mitzvah is to shake us—tent dwellers--out of our docility and into the necessarily physical avoda of mandatory war. Which reminds me, I heard a dvar Torah from R’Ari Kahn that it was the avoda of Yakov to unite his kol with the yadayim of Esav. He did this to defeat the sar of Esav. In the archtypical battle against Amalek Moshe Rabenu sends Yehoshua to fight, but also raises his yadayim. He, a Levi, is engaged in tefila, using his hands, while Yehoshua of shevet Yosef is fighting. Hur of shevet Yehuda is at one side. Aharon the kohen gadol is on the other. This is how we fight Amalek.


E-Man said...

I agree with most of what you said. However, I personally think Amaleik has been defeated. They are no longer in existence (Unless they are hiding underground). Therefore, the actual war against Amaleik is over.

However, the idea that the Jewish people must prevail and even resort to physical force to protect the nation against all of our attackers is still alive. This is why I think the State of Israel is so important, we are supposed to defend ourselves when necessary and this can only be done when we have a physical nation.

That being said, even if the war with Amaleik is not over, I don't know if when the Moshiach comes (may it be speedily in our days) we will still have the commandment to kill Amaleik. Maybe the erasing of Amaleik was always supposed to be a battle of ideals. However, back in the old days, the only way to change the Amalekeit's ideals was to kill them. Nowadays, we can actually sit down, have some tea and biscuits and discuss things. Maybe, these are all possibilities. Who knows.

Thanks for the idea.