The intelligent bird brain

Nicola Clayton, zoologist and Professor of Comparative Cognition in the Department of Experimental Psychology at the University of Cambridge, UK, and recent guest on the BBC radio program, "The Life Scientific," believes that intelligence has evolved more than once, in apes and in birds -- corvids to be precise.  That's primarily crows, jays, ravens and jackdaws.  In a 2004 Science paper, she and a co-author, Nathan Emery, wrote that

...complex cognition depends on a "tool kit" consisting of causal reasoning, flexibility, imagination, and prospection. Because corvids and apes share these cognitive tools, we argue that complex cognitive abilities evolved multiple times in distantly related species with vastly different brain structures in order to solve similar socioecological problems. 

The socioecological problems corvids and great apes have evolved to solve, say Emery and Clayton, include finding and keeping perishable foods over time and space, and understanding individual relationships in social groups.  Emery and Clayton propose that corvids are more intelligent than any other bird, except perhaps parrots, and their intelligence rivals that of most non-human primates. Indeed, Clayton calls corvids "feathered apes".  "You only have to look in the beady eye and see them watching you," she says.

Clayton told the radio presenter that she had her original inspiration jointly with Nathan Emery, now her husband, who was studying primates when they met as students.  He was working on eye gaze, on which there's been a lot of work in primates, and they wondered whether they could collaborate on a project having to do with that.  But, instead, Clayton was inspired by her daily walks around campus when she'd watch the local scrub jays stealing food from students eating lunch on the lawn.

Not only would these birds hide what they'd stolen for later, but Clayton observed that when they knew they'd been watched as they hid their find, they would re-hide it when no other birds were watching.  This led Clayton and Emery to conceive of the corvid "theory of mind".  Previously, it had been thought that only great apes and humans could imagine the future, and put themselves in it, but to Clayton the fact that these jays were sensitive to others watching, and changed their behavior based on that knowledge, meant that they are able to make interesting inferences and deductions that most other animals cannot.  Dogs bury bones "but nobody has shown they are capable of putting themselves into another's shoes." 

The crow has a brain significantly larger than would be predicted for its body size, and it is relatively the same size as the chimpanzee brain. The relative size of the forebrain in corvids is significantly larger than in other birds (with the exception of some parrots), particularly those areas thought to be analogous to the mammalian prefrontal cortex: the nidopallium and mesopallium. This enlargement of the “avian prefrontal cortex” may reflect an increase in primate-like intelligence in corvids. 

Illustration of the four nonverbal cognitive tools displayed by corvids and apes, which are proposed as the basis for complex cognition: causal reasoning (New Caledonian crow and chimpanzee tool use), imagination (insight in ravens and role taking in chimpanzees), flexibility (western scrub jays' flexible memory for degraded and fresh food items and tactical deception in apes), and prospection (western scrub jays recaching food and chimpanzees carrying stone tools). These cognitive tools interact in different ways to produce complex cognition. [Drawing by C. Cain].  From Science. 

In addition to food stealing and hiding behavior, evidence of corvid intelligence, according to Clayton, includes their use of tools, with tool use defined as “the use of an external object as a functional extension of mouth, beak, hand, or claw, in the attainment of an immediate goal".  They make these tools in ways that suggest to Clayton that they have complex cognition. 

These birds "travel mentally in time and space", that is, they plan for the future, including for tomorrow's breakfast, as described here.  They can remember where they've hidden food; Clark's nutcrackers cache up to 30,000 pine seeds which they can retrieve up to 6 months later.  Some corvids cache perishable foods, but don't eat them past their sell-by dates.  These birds can watch others caching foods and pilfer them later, when the storer's not watching.  Or they'll hide their stores behind barriers so that observers can't see its exact location, as in the video.



These birds may well be able to solve these 'socioecological' problems, but we do have to be careful about defining 'intelligence' in human terms, which is at least a bit circular.  After all, other birds, closely related, relatively speaking, do perfectly well at what they do, and that involves using the brain to solve problems, assess their situation, and so on.  This doesn't take away from corvid achievements, of course, but helps put things in perspective.  If corvids actually have markedly better abilities at some kinds of problems solving that we seem to relate to our own, and are closely related to species that don't, then it could suggest that something relatively simple can lead to major jumps in such abilities.

Still, it's always interesting when human, or primate exceptionalism is challenged.



 

Idiocracy is always looming, but not because of genes

As the first day of the semester approaches and the clenching sets in, my mind digs up irksome questions that I’ve fielded in past classes. Usually I mentally rehearse how I can most awesomely answer them, but for one issue in particular I’m launching a pre-emptive strike right here.

In my course Human Origins: Intro to Biological Anthropology a student will no doubt insert the movie Idiocracy into a question. And this never fails to annoy and befuddle me.

And it’s not because of the self-righteous tone that so often accompanies mention of that movie. Though it doesn't help.

And it’s not because I don’t care for the movie. We bought the DVD and the dialogue has really spiced-up domestic banter. (Unfortunately all of our favorite quotes are inappropriate for this venue.)

It’s because, in an educational setting, Idiocracy opens up a huge can of worms, too sophisticated to properly address in the first few days of an introductory course. And yet the can of worms can't be ignored once it's open because Idiocracy's take on the heritability of intelligence bows to common misconceptions held by all sorts of people.

So it's a case of misconceptions being perpetuated by culture. And in our case the culture (movie) that is perpetuating the misconceptions happens to be satirizing the fact that culture perpetuates misconceptions. Trippy.

But like I said, it also plays on half-baked assumptions regarding genes and intelligence.

If you haven’t seen it, the movie’s plot is just about an average guy who finds himself 500 years in the future with the task of saving the world. That future world is Idiocracy where nothing works, where politicians are mere entertainers (um?), where pilots, lawyers and doctors are “tarded,” and where someone decided that sports drinks are better for crops than water. Yep, they’re so stupid that they killed their food and fertile soil. With his average intelligence from 25 generations ago, our hero shows these idiots how to fix their problems. All of this is based on a simple premise that’s briefly outlined in the first few moments of the movie:

IN A WORLD…. where intellectuals have little reproductive success…. future generations are populated by non-intellectuals….and the cumulative result of each generation’s increasingly widespread stupidity is… Idiocracy.

By describing my own fertility when I explain reproductive success, students who are already privy to these sorts of demographic trends discover that I fit the norm for a female university professor. These real patterns are the basis for Idiocracy’s fictitious premise and lead me to unwittingly help my students connect dots that shouldn't be.

Also, it’s one of the few Hollywood films to conspicuously invoke evolution that my students have seen, so it’s a convenient mental touchstone while they experience my course.

I get it.

And here's why it's a problem...

If they take further classes in biology or biological anthropology then they will get a more sophisticated perspective and experience. But for first-timers to evolution (= many of my students) just taking one General Education course at a university is not enough. Chances are that they’ll actually buy into the movie’s premise after my course, simply because their radar's tuned to genes and evolution yet they aren’t solidly equipped with the tools to think critically about it all yet.

So, for the fun of it, let’s lay out the trouble with assuming that if the world’s intellectuals stop reproducing then future generations will be stupid.

• A person’s intelligence (i.e. how it is greater or lesser than someone else’s within the normal range, however that may be quantified) is not significantly determined by genes.

• People can improve their intelligence with training, practice, learning, etc... You don't come out of the birth canal all set to be Bill Gates or an astronaut. You need quite a bit of environmental impact to become anything that you are or might be. If you think of intelligence in terms of potential, most people on the planet never cultivate as much of it compared to what the privileged few are able to.

• A person’s intelligence (again, within the normal range) does not correlate with the level of education they receive. Although people try to make it so. IQ, SAT, and other tests are (1) assumed to measure a person’s intelligence and (2) used overtly and covertly to discourage and encourage young people within the educational arena.

• Education can improve your intelligence which can get you more education which can improve your intelligence which can get you more education which can improve your intelligence.

Given the tangled complexities of genes, intelligence, and education, would you assume that if highly educated people stop reproducing entirely that the next generation will be any less intelligent? NO!

What’s more, you can’t on the one hand assume that variation in human intelligence is determined significantly by genes and then on the other hand assume that you’re smarter than your parents.

Wouldn’t you agree that our individual intelligence has only increased compared to that of our ancestors? It’s not necessarily because alleles that code for greater intelligence have become more widespread than before. That may be true, but it’s undetectable…which doesn’t mean that genes are an insignificant contribution, but it supports the notion that they are not a large factor either.

You may be smarter than your parents or your siblings (or you may not) and that could have everything or nothing or betweenthing to do with genes.

Let’s go back deeper in time to our geologic parents. We share a common ancestor with chimps that lived 6 million years ago. We’re pretty sure we’re smarter than chimps. (This is according to cognitive measures that we’ve created, not them, but okay.) Thus, we assume that our ancestors were not as smart as us, yet we’re here today as these smart beings. Sure genomes have evolved during the last 6 million years, but is it really true that we're more intelligent today simply because the most intelligent individuals contributed to the gene pool during all that time?

(For a related treatment of human intellectual evolution click here.)

And back to the main point....Your particular level of normal intelligence hasn't been shown to be disproportionately impacted by anything that you inherit genetically from your parents.

Your intelligence is about (1) your genes that influence all sorts of interconnected machines and networks in your body, both outside and inside of your brain, (2) your environment’s impact on your body, including the establishment of neuronal networks (i.e. from family, teachers, stimulation, training, food, health, etc…), and (3) all the technology and innovation that has come before this very moment to which you may or may not have access.

Can you blame your parents’ genes for all of that? No. Intelligence is a complex trait with normal variation between you and your parents, me and my parents, and you and me that cannot be causally linked to the stretches of DNA that are either similar or different between us.

Now, without introduction, I ask you to perform a simple exercise…

Think of the smartest person you know.

Got it?

Now think of the wealthiest person you know.

Got it?

Okay, now scroll down…

Are they the same person?

For the majority of people (of whom I’ve asked this question), the answer is no.

Yet when you look at a globe, where are the strong economies? Where is the wealth?

The strongest economies and the wealth are located in regions of the world that are often considered (along a spectrum of naivete to racism) to harbor the most innately/genetically intelligent people.

For reasons that must be due to our evolved ability (sarcasm!) to seek out and dream up causative correlations, the global distribution of wealth leads so many of us to assume that (1) variation in innate intelligence is distributed in the same pattern, and that (2) intelligence causes wealth even though the reverse is also true: Wealth causes intelligence.

Wealth also causes wealth causes wealth causes wealth.

(And intelligence causes intelligences causes intelligence, too.)

Wealth also builds super-comfy superiority goggles. Even ones that fit snugly on the poor, undereducated folks within wealthy populations!

If you chose two different people for that silly exercise above, then you've helped to demonstrate that patterns and associations that we make between intelligence and wealth at the population level (e.g. Japan is wealthy because it's full of superiorly-genomed Japanese people) do not always fit those that we see in our daily lives. Yet we rarely question ourselves when we apply those causative patterns to populations. 

Accounting for individual variation among those we know is one thing we're good at, however, resisting the urge to generalize is not.

The misconception played-up by Idiocracy—that genes govern intelligence—is the basis for claims that biological “race" explains the distribution of wealth in the world. Philosophy like this has supported the killing of millions of people throughout our history.

This flow chart I've drawn for you describes this completely wrong view of genes, intelligence and wealth. (Click on the diagram to see it in full readable size.) We confound the accumulation and transmission of culture (knowledge and wealth) with the transmission of genes. And that’s not entirely due to our ignorance. These are complex issues!

But these are also very old mistaken ideas that persist despite generations of people living their lives and collecting their own experiential data and despite a couple hundred years of scientists and scholars professionally aimed at finding the causes of variation in intelligence, let alone the definition of intelligence.

You’d think we’d be further along than this...assuming so much even though we know only that intelligence is a complex trait. But that habit of ours of establishing causation for all correlations is mighty strong!

Especially when that convenient cause (our special personal genomes and our superior ancestral stock) makes us feel so good about ourselves.

Especially when that convenient cause lets us off the hook for helping the less fortunate because, well, they were born that way. Whaddya gonna do?

This second flow chart is a stab at a more realistic view of genes, intelligence and wealth. (Click on the diagram to see it in full readable size.) It’s not as gloriously and utterly hopeless as a previous flow chart I posted here, but I hope it reflects the complexity of the biological and cultural forces involved in intelligence.

Relative to the first flow chart above, this second one is not such a great recipe for a Hollywood plot is it?

Oh, c’mon... Idiocracy is still a hoot even if the biology's not true. I mean, who doesn’t adore Ghostbusters even though there is no such thing as ghosts?

Please go ahead and LOL and ROFL at Idiocracy... you just have to cleverly ignore its evolutionary ghosts.

And when the movie’s over, and you’re all done laughing, please heed the intended satirical message of the movie:

In a world... where the intellectuals (not an exclusive group!) are stopped from protecting knowledge and passing it down to future generations....future generations are intellectually compromised ....and they seem really stupid.... and they suffer terribly as a consequence.

See, the movie's not entirely a joke.

Idiocracy looms as a threat over all of our freakishly huge heads. And, yes, I mean to use that word exactly as Fox News does. It's a threat that humans have had to avoid ever since our ancestors fared better (i.e. they out-survived and out-reproduced others) if they passed knowledge down to future generations. This has probably been going on for a very long time given how many other animals learn behaviors from each other.

And this age-old threat, that we must keep up proper education or else suffer the consequences, is still here with us today.

And what are people without scholarly merit doing on our school boards? They're purchasing textbooks written by inept Googlers.

Too many science educators are teaching under fear of repercussion. Too many are asked to tolerate or even respect a specified few false folk biologies. While, as far as I know, not a single English teacher has been asked to tolerate or respect grammatical errors.

I mean, You better learn proper English or else go back to where you came from--Right?

What about, You better learn proper science or else go back to being primordial goo?

And the breathtaking inanity of it all is that the ones issuing the threat of idiocracy are actually members of a species that has depended--more than any other organism on Earth--on the accumulation and application of knowledge!

Oh, I guess it's not so inane if you think intelligence and knowledge are innate, god's gift, mostly opinion, and come from the gut.

For many of us in education biz, the Apoca-Lapse of Reason that is portrayed in Idiocracy is even scarier than other doomsday scenarios we see on the big screen and read in books.

The Road? Pshaw. At least I'd die pretty quickly. Living for fifty more years under an idiocracy? Now that's dreadful.

Perhaps I laugh so hard at Idiocracy because if I didn’t laugh I’d cry.


Notes (added January 9, 2011)
1. I do not share commonly held views that IQ is a perfect measure of intelligence, that it is fixed sometime during development, or that mother nature would particularly care about what IQ tests measure (among "normal" people).

2. There is a body of literature on just about every single thing I discuss in the above and it is highly contentious, full of contradictory evidence and debate. However, you cannot dispute the role that status, stress, nutrition, wealth, culture (and more) play in the variation of IQ scores, educational success, and brain and body development... all three of which are involved in "intelligence."

3. There is good reason to believe that components of intelligence are plastic and can improve during life. (Intelligence must be plastic or else you'd have what you've got now as an embryo, but I mean during adulthood too.): http://www.pnas.org/content/105/19/6829.full

4. My use of "intelligence" is not scientific, but that does not make the concept insignificant. In this post, "intelligence" is what we're all able to assess in someone through interacting with them and I think this is a meaningful use of intelligence for this discussion even though it's not quantifiable.


Please read all the comments below by all, not just me. This post is not complete without them.

Really something to crow about!

We used to think that we were Man the Toolmaker, because that was what made us uniquely human. Then, we lost our special place to other clever primates, who also could use tools. Marvelous, stunningly surprising, if humbling.

Step by step we are returned to the ordinary. But crows? Could they, too, put the kabosh on our egos? Of course, it's been known that they're clever (after all, Rossini wrote an opera, The Thieving Magpie, about that!). But you have to see this story and video from the Beeb. Here a crow uses a sequence of tools to get his treat. Apparently, according to the story, they do it even without prior exposure to the layout, and on the first time.

Maybe we have to even farther down the evolutionary Chain of Being before we get to the bottom of our uniqueness. But birds and humans have been separated for hundreds of millions of years, so this means that it's not an evolutionary shared trait (too many dumb-bell species on the way up both branches?). It evolved independently. That's even worse, as it makes IQ even more ordinary.

Oh, well, we're still the only species that can throw a baseball (at least, guys can....)

Did my genes make me do it?

David Brooks of the New York Times seems to be heavily into neuroscience these days. Having dismissed evolutionary psychology some time ago, he's apparently not going at this to understand the genetics behind why some people vote Republican and others Democratic (though there are people doing just this), but perhaps instead in the hopes of understanding how people can be taught to vote Republican. He tells in today's column of his recent attendance at a conference on neuroscience, to his surprise a conference of and by the young. He says

Young scholars have been drawn to this field from psychology, economics, political science and beyond in the hopes that by looking into the brain they can help settle some old arguments about how people interact.

These people study the way biology, in the form of genes, influences behavior. But they’re also trying to understand the complementary process of how social behavior changes biology. Matthew Lieberman of U.C.L.A. is doing research into what happens in the brain when people are persuaded by an argument.

Examples he gives of the kinds of studies being done include:

Reem Yahya and a team from the University of Haifa studied Arabs and Jews while showing them images of hands and feet in painful situations. The two cultures perceived pain differently. The Arabs perceived higher levels of pain over all while the Jews were more sensitive to pain suffered by members of a group other than their own.

Mina Cikara of Princeton and others scanned the brains of Yankee and Red Sox fans as they watched baseball highlights. Neither reacted much to an Orioles-Blue Jays game, but when they saw their own team doing well, brain regions called the ventral striatum and nucleus accumbens were activated. This is a look at how tribal dominance struggles get processed inside.

Brooks' point seems to be that people are malleable, and can be socialized to overcome tribalism or anti-social behaviors -- he has been writing about this for years, contending that poor Americans need to emulate the behaviors of middle and upper class families to have any chance of success. Once we understand how the brain works, he suggests, then policy wonks will "see people as they really are".

But how will that help, really? Even if neuroscientists show us that culture is taught, and people are teachable, who gets to decide who's the best role model? David Brooks thinks he knows, but so do Glen Beck and Rachel Maddow--and the rest of us. So, even if we ever do understand how the brain works, the politics won't get any cleaner or easier.

To us, though, the point is deeper than this. What it takes for major league pitchers to learn to throw a baseball so skillfully, and for violinists to learn to play the violin, and for anthropologists to learn to age and sex skeletons is practice--maybe 10,000 hours of practice. We didn't evolve 'to' do calculus, or play the violin, or throw a baseball or to agree or disagree with Rush Limbaugh, but instead to be able to learn how to do these things (although Alfred Wallace, the co-discoverer of evolution, became quite spiritual in later life, certain that humans were above nature because we could do calculus; he couldn't imagine how our ability to do math could have evolved).

The brain is plastic--learning changes synapses. Indeed, physiological changes in the brain from learning new tasks are measurable, as reported in a recent Nature Neuroscience paper on changes in the density of gray and white brain matter in subjects learning to juggle, described here. And, CNN is reporting on their website today about a woman who apparently had a stroke prenatally which destroyed half of her brain; many of the functions stereotypically performed by the missing part of her brain have been taken over by the active side.

It is natural, especially within western culture with its focus on cause and effect, to seek (or hunger for) simple causes for 'effects' we are interested in. We put the word in quotes because from the inquiry point of view what constitutes an 'effect' is often quite subjective. Is the party you vote for a meaningful effect, or is your vote based on deeper issues that, at present, you find affiliated with some particular party?

It is easy to think about finding the gene 'for' some specific effect, especially if you define the effect meaningfully. It's the view that evolution has hard-wired us for the effect, DNA being the prescriptive cause. But that may have things quite backwards. It makes more evolutionary sense that organisms be programmed to be facultative in sensing, assessing, and responding to the environment. If the human brain is anything it is like that rather than hard-wired for voting this way or that. Even ants, as Darwin observed, seem quite intelligent if we shed our anthropocentric biases.

However, it is much, much more difficult to think of understanding the genetic basis of facultative assessment and response, than of hard-wiring. We don't have good ways to define the trait, much less to find its genetic basis. Yet, clearly, that is the trait we should be trying to understand.

My brain is no bigger than a caveman’s

Many people, including myself, consider Richard Dawkins to be well above average when it comes to intelligence.

So is the size of his brain above average too?

Not necessarily.

Nobody has discovered a way to use a person’s intelligence to predict their brain size and vice versa.

What’s more, all of our brains are no larger on average than those of half-million-year-old “archaic” humans - the kind of people who hunkered down in caves to rest between hunting expeditions or to hide from hungry saber-toothed cats.

In spite of these issues - in spite of it being impossible to use someone’s head size to predict their IQ score or even to predict whether they are simply above or below average in the intelligence department – so many of us mistakenly cling to the notion that that “smart” people have bigger brains than “stupid” people.

It’s partly evolution’s fault.

Evidence from the fossil record and from comparative anatomy of living species makes it clear. Along with body size, an increase in brain size is a common trend in many evolutionary lineages. Over the last two million years our lineage experienced an extreme increase in brain size. And although it has not been as pronounced in other lineages, encephalization has also occurred in apes, monkeys, elephants, whales, carnivores, birds, cephalopods, etc. Mother Nature certainly likes big brains, but she would never ramp up the growth of something so metabolically and developmentally expensive if there wasn’t a payoff. We assume this has something to do with brain function, or intelligence.

Even those who know little or nothing about evolution (or deny it happens all together) can make the connection. After all, our brain is where our intelligence lives and our brains are conspicuously large. We can do all sorts of wonderful things that other animals cannot, so of course our large brains play a role in that.

It is hard not to apply this logic to the variation that we see within our species. But we shouldn’t.

And neither should Richard Dawkins as seen in this recent interview…[start at minute 4]

What’s the big deal? What’s wrong with what he said? It sounds pretty reasonable. Aren’t I just reacting too sensitively to his use of the fact that less educated people have more children than highly educated ones? They do. He’s right. We shouldn't have to be politically correct about facts. I sound like a knee-jerk liberal. Okay okay.

The point here is not to bark about Dawkins potentially misspeaking. He may wish he had said things differently here, and Darwin knows that I wish that very thing after most teaching bouts.It’s just that his hypothetical future evolution scenario was supposed to clarify evolution for the public, but it only raised questions and further supported racist beliefs. Ambassadors of Evolution should be more careful.

Looking around the animal kingdom, it is clear that brain size is correlated to intelligence. Those animals with big brains are the most intelligent. Our common mistake lies in applying that observation to modern humans and towards understanding our current variation in brain size and intelligence.

Whatever drove human brains to achieve modern size about 500,000 years ago is something that unites us all. This is true regardless of our current variation. And this was a type of intelligence, which we all carry with us, that laid the groundwork for all the cognitive and cultural development that has occurred since.

So the development of art, farming, calculus, plastics, microchips, neurosurgery, crossword puzzles, etc… all that stuff (all of which is a big part of intelligence estimations and measures) has nothing to do with why our brains got big in the first place.

Of course intelligence varies between people. But if brain size and intelligence were linked in our species, wouldn’t we be able to spot an intelligent person just by looking at the size of their head? Wouldn’t NASA and Harvard measure heads just to keep their applicant pools in check? Wouldn’t women give up trying to compete with men who have bigger brains than us? Wouldn’t people who wear small hats give up their Jeopardy! or architect school ambitions or just never dream them up in the first place? Most of us already know, whether we realize it or not, that brain size and intelligence are not linked anymore in the hominin lineage.

Once we get past that, then we can ask a couple of really interesting questions.

What did Mother Nature find so fascinating about our brains 500,000 years ago? What kind of function was our brain providing in the middle Pleistocene that required it to be so big back then?

Stone tool technology - which is one of the few things that is preserved from this time period – steadily advanced and became more and more elaborate and complex during this phase of our evolution. So, invention and technological intelligence, which goes along with physical intelligence like manual dexterity, is a good explanation for our encephalization. Another strong hypothesis suggests that social networking was so utterly important to our survival and reproduction that only with a larger cortex could a person maneuver and compete within a large society full of other intelligent creatures. Political games, power struggles, relationship forming, relationship maintenance, and resource acquisition (e.g. cooperative foraging and hunting) may have all relied on a big social brain. Language was another likely brain size booster.

Given that the trend for increasing brain size began 2 million years ago and lasted for about 1.5 million years, why did it just stop in the Middle Pleistocene?

Maybe we had all the brain we needed. Look how far we’ve come with caveman-sized brains!

It’s also possible that this is as big as it gets: Metabolic and developmental constraints may prevent our brains from getting any bigger.

Okay, so Dawkins jumbled up the story of human brain size evolution and intelligence. Still, what’s the big deal? What part of it flirts with racist beliefs out there? If you look back into the history of science and pseudo-science, there is a long tradition of measuring heads in different human populations and a long history, which continues today, of concluding that some “races” have smaller brains than others. There is also a long-held belief that some races (which are historically grouped by geographic origin, skin color, language, and other cultural traits) are more intelligent than others. In both brain size and intelligence, guess who gets ranked lowest most often in these "studies"? Africans and people with African ancestry. So to determine if someone is intelligent, we might take into account skin color, nose shape, eye shape, and cultural factors like language and body adornment. Dawkins's misstep adds unfortunate credence to this pseudo-scientific nonsense.

One big confounder is that we know very little about what causes variation in human intelligence. We know that intelligence is not determined by genes alone, but that genes do play a role since they build the brain. Natural Selection could act on these genes and drive evolution, as Dawkins said. However, intelligence is much more than “good genes”. Something as simple (but often so hard to obtain in a crowded world) as good nutrition contributes greatly to neurological and cognitive development.Environment is another key factor. Stimulation, practice, learning, and discovery, along with a healthy diet, help children become mental gymnasts who can grow up to qualify for the intellectual Olympics. It seems to me that if we put the need for nutrition and education programs in terms like, “Granting all Americans the opportunity to be intelligent citizens,” there may be may be more taxpayer support.

As Ambassadors of Evolution, it is our duty to clarify for others what we know and what we don’t know about the evolution of the human brain and intelligence. Even more than the “aquatic ape” hypothesis, the evolution of intelligence is consistently the most popular topic in public and classroom discussions of human evolution, and yet is the most dangerous given our sordid history, but having this discussion holds the potential to improve the human experience.

- Holly Dunsworth, guest blogger

Further Reading:

Race is a Four-Letter Word: The genesis of the concept by C. Loring Brace (2005)

Everything else is but a detail...

It's been said that once the cell evolved, everything else in life is but a detail. It sounds like glib reference to the fact that all life (well, all cellular life--viruses excluded) is cellular. But as we've noted in an earlier post on cognition in bacteria, and in our books and writing, even single-celled organisms have complex abilities to evaluate and respond to their environments. Those abilities include, in many or even perhaps most such organisms, the ability to form multicellular organisms under some conditions (slime mold, bacterial biofilms, and others).

In fact, this is not a trivial kind of exception, but a profound one. The same kinds of mechanisms that make you a single, multicellular entity lead otherwise single-celled organisms to do remarkable things. These 'simple' cells have sophisticated ways to monitor their environment, respond collectively (even sometimes as collections of different species) in response. That is, they are adaptable, one of the basic principles of life.

An example that has been noted by others, but that we learned about this week on the BBC World Service radio program, The Forum, with biologist Brian J Ford, is the amoeba called Difflugia coronata. This single celled organism, living in ponds or other watery worlds, builds a house of sand which it lives in and carries around as it moves. The house is 150 thousandths of a millimeter in diameter, but apparently carefully constructed in a replicable form. As the amoeba grows, it ingests sand of varying sizes and when it divides to reproduce, one of the daughter cells inherits the house and the other gets the ingested sand so that it can build a house of its own. You can read more about it in the book, Built by Animals: The Natural History of Animal Architecture by Mike Hansell [Oxford University Press. 2008] (which can be found online in abbreviated Google form here). This gorgeous picture of one Difflugia's house is from that book.

It's not only the amoeba, of course. Cells of red algae even circle around a wounded peer, protecting it from the outside environment and providing its physiological needs until it recovers. And so on.

If we think about life in this way, and not in terms of exceptionalism for 'higher' organisms, life becomes more of a unitary phenomenon. Also, many things, including perhaps especially behaviors, that we might wish to credit adaptive evolution for having produced in our own precious ancestry as a species, have been around billions of years before the first hominids had that lusty gleam in their eyes. And, with little doubt, these 'primitive' amoebae and algae will still have their orderly social life eons after we advanced creatures have departed this Earth.