Are Humans Dumber Than They Used To Be?

As we look at what goes on here on Planet Stupid, there can be little doubt that, on the whole, humans are dumber than rocks. It doesn't take a lot of work to come to this conclusion. Simply read a newspaper or watch a media newscast, or read the daily headlines at The Business Insider. But are humans dumber than they used to be? That's the thesis of Stanford researcher Gerald Crabtree. I first broached this subject in my post The Incredible Shrinking Brain.

Crabtree's thesis is described in Is pampered humanity getting steadily less intelligent?

Since modern humans emerged from the evolutionary brambles of our ancient ancestry, our bodies and minds have been transforming under the pressures of natural and sexual selection. But what of human intelligence? Has our cognitive ability risen steadily since our forebears knapped the first stone tools? Or are our smartest days behind us?

Gerald Crabtree, a geneticist at Stanford University in California, bets on the latter. He believes that if an average Greek from 1,000 BC were transported to modern times, he or she would be one of the brightest among us. Our intellectual prowess has probably been sliding south since the invention of farming and the rise of high-density living that it allowed, he claims.

In two articles published in the journal Trends in Genetics, the scientist lays out what might be called a speculative theory of human intelligence. It is, he admits, an idea that needs testing, and one that he would happily see proved wrong.

At the heart of Crabtree's thinking is a simple idea. In the past, when our ancestors (and those who failed to become our ancestors) faced the harsh realities of a hunter-gatherer lifestyle, the punishment for stupidity was more often than not death. And so, Crabtree argues, enormous evolutionary pressure bore down on early humans, selecting out the dimwits, and raising the intellect of the survivors' descendants. But not so today.

As Crabtree explains in the journal: "A hunter-gatherer who did not correctly conceive a solution to providing food or shelter probably died, along with his or her progeny, whereas a modern Wall Street executive that made a similar conceptual mistake would receive a substantial bonus and be a more attractive mate. Clearly extreme selection is a thing of the past."

The scientist draws on recent studies to estimate a figure for the number of genes that play a role in human intellectual ability, and the number of new mutations that harm those genes each generation. He settles on a suite of 2,000 to 5,000 genes as the basis for human intelligence, and calculates that among those, each of us carries two or more mutations that arose in the past 3,000 years, or 120 generations.

All of which leads to the conclusion that humans reached our intellectual height in the dim and distant past. "We, as a species, are surprisingly intellectually fragile and perhaps reached a peak 2,000 to 6,000 years ago," Crabtree writes. "If selection is only slightly relaxed, one would still conclude that nearly all of us are compromised compared to our ancient ancestors of 3,000 to 6,000 years ago," he adds.

It is tempting to play this story as farce—I see dumb people!—but I'm going to take the high road today. I simply don't see how it's possible to test Crabtree's thesis. We can't climb aboard our handy time machine and travel back to ancient Greece to kidnap an average Greek from 1,000 BC and transport him to modern times to see if he would be one of the brightest among us. In fact, if you've read any ancient history, for example, Thucydides' account of the Peloponnesian Wars, written in 431 B.C., you would be forced to conclude that there's little difference between ancient Greeks and contemporary Americans.

On the other hand, I do believe that Homo sapiens, as a species, is "surprisingly intellectually fragile," although I don't find it terribly surprising.

We might ask an alternative question: are contemporary humans crazier than they used to be? In DOTE terms, that's the same as asking are contemporary humans more out of touch with Reality than they used to be? I believe that if we answer this question in the affirmative, we are on much firmer ground. Modern humans are completely out of touch with the Natural World, and have an equally flimsy grasp of what's going on in the large, complex (but structurally predictable) societies they have created.

Technological "improvements" in mass media have created a situation in which the consensual Reality is now almost wholly defined by other humans whose conscious or unconscious agenda constantly shapes our perceptions of what's going on. In that sense, for contemporary humans, physical and psychological Reality can hardly be said to exist. Thousands of years ago, humans could perceive directly what was happening around them and to them. That's not the case anymore. Now there are layers and layers of obfuscation separating humans from direct apprehension of events. In Crabtree's terms, direct evolutionary selection pressures no longer exist. You are usually not killed off by the person right in front of you (although that still happens). Now you are screwed by a sociopathic banker on Wall Street who you don't know and who doesn't know you.

For example, polling reveals that Americans have no clue about the extent to which this society has been divided into Haves and Have-Nots. And last week, 120 million Americans voted for Democrats or Republicans, pretending all the while that it matters whether one political party or the other holds power, although the relatively low voter turnout was encouraging. Both political parties have sold them down the river over the last 30 years. Generally speaking, social realities have been nearly obliterated.

Are humans dumber than they used to be? I don't think the answer matters much because humans have always been dumb. Technologically clever, yes, but generally intelligent? No! The fundamental irrationality, the tendency to believe in invisible beings who watch over them, the belief in magic, the unwarranted optimism, the stubborn, false Hope which flies in the face of Reality, the tragic lack of self-knowledge—these, and a thousand other flaws have always been there.

So as far as I'm concerned, our species was pretty "dumb" to begin with. This great truth has always been hidden from sight because humans have such a high opinion of themselves. Humans think they're the greatest thing since sliced bread, and who is there to contradict them? 

Being divorced from natural selection pressures has probably influenced who we are to some small degree, as Crabtree maintains. Maybe we have been dumbed down a bit. That said, the only authentic answer to the relative stupidity question is that our species Homo sapiens is what it is, humans have always been this way, progress is an illusion, and what you see is what you get. And that will never change. Our species will be true to itself right up to the bitter end.

Comments

[James]

The posts on human genetic decline are purely speculative and ignore that evolution is driven not by purpose, but chance. Evolutionary adaptations are as likely to be random as anything (see fly eye coloration). Humans didn't necessarily survive by being "smart"- brutality and dedication work just fine. The ancient Greeks are a fine example.

In the first millennium BCE, we see the rise of several ancient societies. Mahna Graecia is colonized. These early settlers are tribal and eventually developed into armed city states. The dominance is marked largely bu military capacity, with bronze age cultures dominating the neo-lithic peoples from the third through the second millennium and, in turn, bowing to iron age cultures and the development of steel in the 1st. The later half of the millennium is dominated by warfare as rival city states exert dominance. Later, power would shift to the burgeoning Roman Republic and its wars with Carthage.

So, prosperity and "culture" came not by some clever innovation, but by who could muster more spearmen and superior arms. The first western empires were already developing and empire was already well established in the near East (Egypt,etc). Humanity quickly became its own biggest threat. Rome rose ascendant during this period.

Can anyone honestly say that we are that different from the Romans? It is pretty much the prototype for every subsequent western civilization, either in the republican or, much more commonly, imperial mode.

History keeps repeating itself precisely because humans don't change that much. We just develop better weapons, building materials, etc. But in the end, we are still the same short sighted, superstitious, violent, greedy primates we always have been.

[Dave Cohen]

So, James, do you actually bother to read my posts?

-- Dave

[Brian M]

Dave: My biggest skepticism is the thesis that "primitive" humans really understood more directly what was happening to them. To borrow the title of a late work by Carl Sagan, in a Demon-Haunted World, you may see what is happening to you, but you often explain it through references to supernatural forces. Solutions are often invented via deferral to oral "traditions" that may be effective...or may not be.

[Dave Cohen]

@Brian M

Well, you didn't understand my point, did you?

I didn't say "primitive" humans understood more directly what was happening to them. I said they experienced what was happening to them more directly.

If it didn't rain, or game animals were scarce, you didn't eat. Now, people see food prices go up, or their incomes go down, and they don't know the real reasons why that is happening.

These "primitive" humans would do a little dance, or they would perform a ritual sacrifice, to make it rain, or scare up some animals to hunt. Now we consult economists, who tell us it's only a matter of time before the rains come and the game animals return. Whatever.

I'm sorry, but I'm not feeling very tolerant today, especially after writing a post on how dumb people are.

-- Dave

[Tom Durkins]

Excellent post Dave. I just finished rereading Jerry Mander's "Four Arguments for the Elimination of Television" and your paragraph beginning with "Technological "improvements" in mass media have created a situation in which the consensual Reality..." REALLY resonates with his ideas regarding TV and mass media in general. It's remarkable that the book was written 35 years ago. Even for someone like myself, I find it very difficult to sift through all the human layers of BS that cloud what used to be defined as reality/nature.

BTW, I also liked "The thing about smart people is that they seem like crazy people to dumb people". So true...

~Whipping Boy

[Oliver]

A very eloquent essay Dave, and one that I am especially glad to read, having recently been in the company of some human biologists (or is it biological humanists) who seem to take exception to the idea that we are a flawed species from the genes up, with all the attendant dumbness and misplaced egocentricity that you have regularly discussed here.

It does occur to me - and it's the only kind of salvation that has any meaning - that maybe there are genetic mutations walking around among us who have "progressed" beyond the Homos sapiens jail cell, and have gained the apparatus to experience Reality - i.e. they are truly smart, not some mixture of clever/sly/crafty/manipulative/scheming/Machiavellian/me-me-me attributes (yawn).

As you indicate, they would seem like "crazies" to the average human ape, because they conduct themselves way out of the ordinary compared to the dumb normality of the great majority.

[mudduck]

I've been wondering whether there's only so much intelligence available, and it's being spread thin over an out-of-control population. Crabtree's pointing out that modern human beings don't have to be particularly sharp to survive makes more sense. Weird, the conviction possessed by people of (mostly inherited) wealth that their riches means that they're smart. We need a restart with people whose position rests on actual achievements.

[Mike Roberts]

Looks like a very readable post but I don't have time to read it right now, so sorry if this comment is irrelevant. I remember reading a preview of a Sciam Article about increasing IQ scores. If that is right, I suspect that IQ tests measure anything but smartness.

[P.S]

Right on, Dave.

I'm posting this as Exhibit A:

http://www.guardian.co.uk/culture/2012/oct/09/like-a-hug-facebook-vest-friends

The best and brightest at MIT are really pushing the boundaries of human vacuity.

[clyde]

Evolution isn't a linear process. It waxes and wanes as mutations are selected for, or not, by how they fit (survival of the fittest) their environment.
As it stands, our Western/developed world environment seems to select for any old mutation since we have made an extremely cozy environment for the human, i.e. we look after those with disorders, feed those that cannot feed themselves and so on. As we do, their genes propagate.
It goes without saying that that environment is due for a change.
Whether any of our billions of humans can come up with the necessary mutation to take us further into that changed/changing environment, we will not be around to find out.
But life, once established, is very difficult to fully extinguish and I expect that we will evolve into something that will eventually fit, even if it is another species altogether.
Interesting times, indeed.

[Ean "Get me off this Planet" Gray]

I have nothing more to add, as it would reduce (or repeat, unnecessarily) the intelligence and clarity of this post. That was a solid analysis-- thanks.

[Aboc Zed]

@clyde,
i liked your comment very much would appreciate a way to contact you for further dialogue if interested
thx
za

[Brian M]

Grumpy! I guess I was reacting more to a "Noble Savage" meme than your post per se. What you point out...sure.

We also have to listen to the pseud-scientific blatherings of "geneticists" who (as you actually do note yourself) have absolutely no means of even studying this issue...but maybe the decline in intelligence is better exemplified by the "media".

http://thisislikesogay.blogspot.com/2012/11/dumb-humans-think-humans-getting-dumber.html