I love Greg Dean’s webcomic, Real Life. It has some moments of true hilarity in it, and I find the characters enjoyable enough that I’m thrilled to see each new comic pop up in my RSS feeds. But today’s comic contains a howler which I just can’t let pass. If you don’t want to go read it, the fun is in the final panel where one of the characters says “Hey, it’s not like you were using the other 90% of your brain anyway.”
Now, if you’re literate about neuroscience in any way, this will immediately strike you as stupid; the myth about human beings using only 10% of their brains is wrong, and that’s been known for decades. But to be honest, I could have let this go and just read the comic, until I came across a posting in the Real Life Forums by Greg himself, as part of an exchange with another person who commented on this problem:
Kovac wrote:gaghWhy would you contribute to the myth that humans only use 10% of our brains?
It is for the purpose of a joke, but it just isnt worth it
Allow me to quote Scientific American, so you foreigners can quit being such dicks about it. (Seriously, I’ve recieved another e-mail from someone else today telling us Americans to quit being so ignorant. Is this just a pet peeve of everyone on the other side of an ocean from us, or something?)Anyway, as I was saying:
Scientific American wrote:Another mystery hidden within our crinkled cortices is that out of all the brain’s cells, only 10 percent are neurons; the other 90 percent are glial cells, which encapsulate and support neurons, but whose function remains largely unknown. Ultimately, it’s not that we use 10 percent of our brains, merely that we only understand about 10 percent of how it functions.
NOW. While I will grant you that the concept that “we only use 10% of our brains” is silly, it’s also been used for DECADES as the basis for a lot of fun “what-if” style storytelling. Powder and Phenomenon are two excellent movies that come to mind which deal specifically with this idea. So, I think what I’m saying is, quit being such a fucktard about something so INSIGNIFICANTLY POINTLESS as this, and just try to enjoy the fucking comic. I’m sorry if I’m getting a little on the offensive here, but this pedantic bullshit just pisses me off. Especially when it’s passed off in the guise of “Gee, you Americans sure are stupid.” (I know you didn’t do that specifically, but that was the tone of the other e-mail I recieved, and it stuck in my craw a little.)
Here’s a couple of points in response, Greg:
- Really – you’re going to base your argument on the past usage of science in media? Seen a lot of 50-foot tall women in the talkies lately? How about books about a guy who goes to the moon by being shot out of a cannon? Even Marvel is smart enough to keep up with advances in our knowledge, if you’ve seen the re-write of the Spider-man origin in the Ultimates universe (from a radioactive spider to a genetically altered one).
- To people who don’t know any better, you’re propagating the idea that there is some locked-away 90% of our brain that would turn us into magical super-heroes if we could only access it. This is a lie, Greg, and it is part of a real issue; scientific literacy in the United States, where you’re from, is shockingly low. This makes you part of the problem.
Scientists like me struggle every day to correct the misconceptions of science in the public’s view, so you’ll have to forgive us if hearing that we should just shut our yap – because you’re too lazy to come up with a plot point that doesn’t depend upon a thoroughly discredited idea from well over a century ago – is a problem for us. And if it’s such an insignificant point (as you say to us ‘fucktards’), why can’t you just get it right?
Oh, and Greg, as for your quoting of the Scientific American article: way to cherry-pick. The “ultimately we only understand 10% of how it functions” bit is a rhetorical closing at the end of the article. I prefer this quote from the middle of the piece:
Adding to that mystery is the contention that humans “only” employ 10 percent of their brain. If only regular folk could tap that other 90 percent, they too could become savants who remember π to the twenty-thousandth decimal place or perhaps even have telekinetic powers.
Though an alluring idea, the “10 percent myth” is so wrong it is almost laughable, says neurologist Barry Gordon at Johns Hopkins School of Medicine in Baltimore. Although there’s no definitive culprit to pin the blame on for starting this legend, the notion has been linked to the American psychologist and author William James, who argued in The Energies of Men that “We are making use of only a small part of our possible mental and physical resources.” It’s also been associated with to Albert Einstein, who supposedly used it to explain his cosmic towering intellect.
Emphasis mine. Or how about this one, from the same article?
Although it’s true that at any given moment all of the brain’s regions are not concurrently firing, brain researchers using imaging technology have shown that, like the body’s muscles, most are continually active over a 24-hour period. “Evidence would show over a day you use 100 percent of the brain,” says John Henley, a neurologist at the Mayo Clinic in Rochester, Minn. Even in sleep, areas such as the frontal cortex, which controls things like higher level thinking and self-awareness, or the somatosensory areas, which help people sense their surroundings, are active, Henley explains.
p.s. Greg, I’m Canadian, not American, so consider my pedantry to be a message from your own side of the ocean.
I’ve been paying attention to Canadian politics as I look forward to exercising my democratic rights ina couple of weeks. I’ve never been seriously interested in the NDP, for the simple reason that they never seemed to be in a position to take power, but with the Liberals melting down in the polls recently, I’ve come to view the NDP as a serious contender for (at least) the opposition. Since I would normally vote Liberal, this now leaves me pondering my choices more carefully.
To help figure out what I’m going to do, I sat down tonight to review the platforms of both the Liberals and the NDP. Mr. Layton’s was interesting, with many ideas on important issues like climate change, the economy, and so on. But if you’ve read this blog for any time at all, you’ll know that I’m a Ph.D student in Biology, and that science is very important to me. So what is the NDP stance on science and scientific research in Canada, you ask?
The NDP platform is weirdly vague to begin with. But doing a search through the document reveals a single mention of the word “science”, and that’s in regards to climate-change. Searching for “research” leads to such vague platitudes as:
[we will…] Encourage the best young minds to stay here in Canada by increasing funding for university and college-based research, and for graduate and post-graduate studies.
[we will…] Introduce measures to ensure that new drugs are evaluated through evidence-based research to be more effective, before they are prescribed by doctors and paid for by Canadians.
[we will…] Work with the provinces and territories to encourage research and develop strategies to minimize the effects of climate change on communities, vegetation and wildlife.
Stop the hollowing out of Canadian industries by strengthening the Investment Canada Act. Foreign takeovers of Canadian companies will be subject to more stringent tests respecting job protection and creation, head office location, and the promotion of research and development in Canada.
That’s literally every mention of the word “research” in the NDP platform (and every single mention of “university” as well, come right down to it), yielding not a single concrete item on the matter. Contrast that with this section of the Liberal platform:
A Liberal government will increase support for the indirect costs of university-based research to $500 million a year, which at full implementation will represent a more than 50 percent increase over current levels.
For researchers and graduate students, a Liberal government will increase the budgets of the three granting councils by 34 percent over four years. Support for the Canadian Institutes of Health Research (CIHR) and the Natural Sciences and Engineering Research Council (NSERC) will both increase to $1.275 billion a year from the current levels of $960 million. Funding for the Social Sciences and Humanities Council (SSHRC) will be increased to $450 million a year from the current level of $320 million.
We will also create an Interdisciplinary Sustainability Fund of $100 million. This Fund will be available to scientists, researchers and graduate students for projects that reach beyond the barriers of their discipline. Interdisciplinary research is the way of the future. It is how we will address complex scientific challenges – like adaptation to the climate change crisis – that affect our economy and our society. government will increase the budgets of the three granting councils by 34 percent.
You see, now there’s a set of hard targets that I can vote on. Seeing as I’m funded (well, I *hope to be* funded) by NSERC, knowing that the Liberals would increase their budget is useful information. Since NSERC and its sister agencies fund much of the public scientific research in Canada, this is a sign that the Liberals would take basic and applied science seriously.
But the NDP? I have no idea what they would do. They’re going to “encourage the best minds”? How? I might be interested in voting NDP, but I just really need to know more than this big steaming pile of nothing that I’ve got before me right now. Jack Layon, or one of your supporters, if you’re reading this: help a guy out. Help me vote for you. Explain what the hell you’re talking about.
I have to admit it: I’m a tab collector. Despite my best intentions, and productivity be damned, I inevitably find myself surfing my RSS feeds, popping open new tabs for interesting looking stories, and then winding up doing something else and forgetting about the tabs until I wonder why Firefox takes twenty minutes to come to the foreground. Which is why I just got around to reading Jennifer Ouellette’s fantastic post about science on prime-time television, and also explains why I’m just getting around to forming my thoughts on her argument.
I urge you to read her post first – she’s the kind of writer I wish I could be, and reading her material is a treat of itself – but if you can’t spare the time, she summed things up in a comment near the bottom:
Stripped of excess verbiage above, my argument is this:
1. TV is quite possibly the most powerful communication medium in modern American society.
2. Anyone who is interested in broad communication to the general public ignores TV at their peril.
3. There is an unprecedented demand for science-themed shows right now, and hence a corresponding need for scientists to serve as technical consultants or participate in other efforts to better acquaint Hollywood with what “real” science looks like.
4. This is made more difficult by an enormous cultural gap between the two worlds: there is fear and distrust of science in Hollywood, and often open disdain by scientists towards mainstream TV, which writers and producers naturally find alienating and irksome.
5. We need more exchanges between the two worlds, and a shift in attitude on both sides, or we will lose an excellent opportunity.
This argument, alone, is one that I find convincing. I’m happy that science is finding a place in the schedules of prime-time programming, though I won’t be too terribly surprised if we’re back to nothing but Survivor-clones when the networks over-use the “science show” idea and the public’s fancy shifts again. Yet along the way to making this argument stick, Jennifer ends up saying two things that bother me somewhat, and I wish to address those points with my own thoughts.
First, she suggests that accuracy is less important than the popularization of science itself (reminiscent of the “framing” arguments which have stirred up so much trouble in the sciblogosphere):
True story: a year ago, I met one of the writers for Bones at Grae’s birthday party. He was initially pleased to find that I really was a fan of the show, and not just being polite. (I knew all the characters and plot twists — a dead giveaway.) But when I mentioned I was a science writer, he suddenly became guarded and defensive: “Yeah, yeah, I know, we take liberties with the science, DNA test results never come back that fast….” I reassured him that I wasn’t one of those sorts who compulsively nitpick the writers to death, and he relaxed a little. But the exchange saddened me a little. Here was this very smart, really nice guy who loves his work and finds the scientific elements fascinating. Yet his personal encounters with actual scientists have been unilaterally negative and alienating — so much so, that he physically recoiled upon first learning about my science writing credentials. That has to change, or the cultural gap will just continue to widen.
I sympathize with the writer who has run into prickly scientists. Yet I would maintain that a higher level of accuracy is necessary on science-based dramas, for reasons both practical and philosophical. Practically, a lack of accuracy leads to things like the by-now-well-known CSI effect, where people have come to expect things of forensic science that are simply not feasible or practical (like the seemingly 8-second DNA analysis and database search that they routinely employ on that show). Responses to this problem typically fall into the “poetic license” category or employ the “sure, but we need to focus on communication over accuracy” argument as Jennifer obliquely makes in the quoted section above, but these responses ignore the real problems that a public misperception of what science can do may lead to (as a prosecutor frustrated by a jury demanding DNA evidence for a simply break-and-enter might attest to), and they also ignore the fact that it is possible to do both accuracy and entertainment. There are shows that are true to the science; as Jennifer notes, The Big Bang Theory has a realistic image of the science and the environment of science itself, and Numb3rs is great for focusing on real mathematics. Writers of science-y shows might do well to learn from Law & Order, which (as I have been told by people involved in law enforcement) presents the best depiction of the real process of justice that is on television, even if it glosses over the more repetitive aspects.
The related philosophical problem with Jennifer’s statement above extends past the purely practical problem of the CSI effect and into the “science is magic” problem. Jennifer criticizes Fringe for flirting with the “science is magic” viewpoint, but doesn’t really take this to its logical conclusion even as she notes the most important part when she says:
Uh, no. That is not what science is about; it’s what science fiction is about. I love both, but let’s not confuse the two.
She’s right: that’s not what science is about. But when shows like CSI or Bones play fast and loose with the process of science and how the world actually works, they actually contribute to the problem not because they are science fiction, but because they’re not science fiction. Science fiction is actually easier, because people can clearly distinguish between science fiction and real science. When the Doctor says that he is going to “reverse the polarity of the neutron flow”, or when someone’s pattern is stuck in a transporter buffer on Star Trek, most people can easily realize that science as we know it does not allows us to do these things. If NASA could suddenly achieve faster-than-light travel, people would be rightly shocked! But though viewers can readily distinguish science from science fiction, they likely have a harder time distinguishing science on television from science in reality. When the television presents a contemporary drama with science as an important element, the portrayal of science in that show can become the only exposure that people have to the science in question, and thus shapes their view of what science can actually do. I don’t mean this in a pomo, constructivist-reality sort of way, but in a much more real and troubling this may be the only time that these viewers are ever going to see how this works way. As Jennifer notes, television is one of the most important mediums of communication in our society today, and the chance that people see a show like Bones is a lot greater than the chance that they sit through a documentary on forensic anthropology on the Discovery channel. Given that, how can we not hold these dramas to a higher standard? Jennifer says that we shouldn’t:
Many scientists I encounter seem to incorrectly think that the scientific details are all that matter. While those are important for lending verisimilitude — particularly for procedural dramas like C.S.I., Bones, or House — network television isn’t an educational vehicle. Hollywood’s purpose is not to teach viewers about science, and TV shows are not documentaries, and should not be held to the same exacting standards — although the two are not necessarily mutually exclusive, provided both sides are willing to compromise a little. Good television is ultimately about igniting the imagination with a truly kick ass story. If we can enhance the appreciation of science (and by extension, scientists) in the bargain, so much the better, but that is not the industry objective.
But this paragraph relies on an argument that goes like this:
If we create television shows that employ “lies to children” but spark people’s imaginations, they will go out and learn the real story, and we will have a more educated public.
It is this argument that I reject as unlikely and even dangerous. Sure, some small proportion of people may go on to have great careers in science or even just learn more in science because of some great drama they watched on television, but the vast majority of people will go no further than their TiVo. If this is to be their only exposure to these concepts, what do we expect to happen when they are on a jury, or on a school board voting about science eduction, or voting for presidents and prime ministers who will shape science and education policy? Jennifer is right in that the networks don’t care about this sort of thing, but to suggest that scientists should just give up and go along with it simply to get air-time is, to my mind, irresponsible and ultimately self-defeating.
The second issue that I have with her argument revolves around the depiction of scientists themselves. Let’s see what she has to say:
Monday night was the season premiere of last year’s breakout sitcom, The Big Bang Theory, which proved to be something of a lightning rod for controversy when it debuted last year, at least within the physics community. (My own take in Symmetry magazine can be found here.) Normally, scientists content themselves with nitpicking various aspects of the science in movies and TV shows, but in this case, the science is largely correct, thanks to the efforts of technical consultant David Saltzberg, a physicist at UCLA. So most of the complaints about TBBT have been of the “negative stereotype” variety.
As I’ve said before, such criticisms might have an element of truth but they are entirely missing the point: these characters appeal to viewers. They are likable just the way they are, and that is a Good Thing for Physics. If the goal is to make physicists feel good about themselves, then okay, maybe this isn’t the best approach. But if the goal is make physics and physicists more palatable to the general public and win their hearts and minds, these characters are fantastic ambassadors. I vote for the latter.
Actually, I’ve used this quote only as a starting point, because I agree with the substance of her argument above (and the argument she advances in a post she links to here) about scientists taking their portrayals too seriously; no comedy (and few dramas, for that matter), get very far depicting characters who are entirely realistic. But my problem isn’t with “negative” stereotypes, but rather “positive” ones. I’ve talked about this before, but shows like The Big Bang Theory, CSI, Bones, Numb3rs, and so on all depict scientists unrealistically as incredibly brilliant people who know just about everything and rarely make mistakes. This contirbutes to the “science as magic” problem by showing us “scientists as magicians”. Here we are effectively told that the only people who do science are super-geniuses with an encyclopedic knowledge of everything in their field and in some cases of things way outside it, who can whip up science in a second and come up with answers to just about any problem. Even one of my favourite characters, Charlie Epps from Numb3rs is guilty of this: though the methods he uses are real and the techniques are sound, he does the work of a dozen people! Any practicing scientist knows that science is a team game now because it’s impossible to be a polymath any more; the days of a single person contributing to physics, chemistry, and biology before lunch and rounding things off with a few contributions to mathematics before tea are gone, and it’s increasingly difficult for people to keep up with the tiny corners of the scientific literature that they inhabit themselves.
Yet as intimidating as these characters are to someone like me, who is a scientist and who actually works at this sort of thing, imagine what they look like to someone sitting on their couch at home. How can we expect to attract people to science if we present nothing but these images of super-people at the lab bench? Again, we can look back to Bones. The lead character, Temperance Brennan, is a genius anthropologist, but her assistant is even worse: a child prodigy, a genius with an IQ of 160+ and packing a “photographic memory” (grrr), yet he always seems to be stumbling behind Brennan (at least in the first season, which is all that I’ve watched so far). If someone like him can’t keep up with the lead character, how can anyone in the audience picture themselves being motivated to become scientists themselves or even spend any time learning more about science? Characters like this present such an incredibly high barrier to entry that it seems futile to even try!
Again, the common response to my objections about this is that people either know the difference between fictional depictions of scientists and real scientists, or that the shows will “spark their imagination”, and they’ll flock to the lab for the drama and stay for the science. And sure, enrollments in forensic science classes surged after CSI became popular. But if you ask a person on the street if they could see themselves learning anything about the science of physics, or mathematics, or chemistry, or biology, you’ll most often get a self-deprecating laugh and refusal, or a blank stare. And this is how we’re going to create greater appreciation of science, by portraying scientists as super-men and women who are something Other? These are the ambassadors that Jennifer speaks of? It does us no good to win the hearts and minds of people if we’re winning them with the scientific equivalent of demi-gods.
Actually, this is something that I’m sure many other academics and practicing scientists have run into: mentioning science, or physics, or – God help you – math to someone who isn’t a science person turns your occupation into something untouchable, something to be placed on a pedestal and admired from afar, despite your best efforts to have a normal conversation with the person in question. And I submit to you that the depictions of scientists on television are a contributing factor for this problem, and that these depictions are something that scientists should be concerned about. I’m all for the need to show heroes on television, but maybe we could take Numb3rs and cross it with the old Mission: Impossible to get a show where a team of fairly bright people come together to solve hard crimes with some cool math, instead of a show where a single untouchable genius saves the day every damn time.
My word count is telling me that I’ve ranted on for far too long, and my body is telling me that it is time to go to bed, so I’ll leave it here for now. I’ll just close with this: instead of satisfying ourselves with what we see on television, perhaps we as scientists, should try even harder to push realistic images of science and scientists out onto the airwaves. I think that society might thank us, in the long run.
Via Panda’s Thumb, I came across a website that I didn’t know about, called Opposing Views, which is a regulated debate site where experts weigh in on each side of an issue and can object to each other’s arguments, while the public sits on the sidelines and comments. I’m a little burnt-out on the whole “go on the internet and convince people” routine, because I’m frustrated at how useless most of these types of conversations are, but this site looks like a good alternative to the standard go-into-a-forum-and-scream-at-each-other thing. Watching the (verified) experts lay out the case for either side is a good way to get a feeling for how strong the arguments really are; for example, take a look at the beating that Steven Novella is giving Bill Reddy on acupuncture. Here’s to the advancement of science!
I don’t watch a lot of TV anymore; when I moved to Montréal, I never hooked up the cable and my television doesn’t even have an antenna, so I haven’t seen anything I didn’t download (legally) or buy on DVD for quite some time. But I do tend to watch seasons of television on DVD, especially when I’m snuggled in with my wife, and recently we began watching Bones together. Watching the depictions of science and scientsts in this and other series got me thinking about the rage-inducing depictions of same on television and in movies, and here’s a few of my howl-inducing favourites:
- Scientists aren’t usually so socially retarded. Many of the scientists depicted on television (including the main character in Bones, as well as most of her team) are depicted as being social morons who can barely manage to wipe their own behinds when left to their own devices. Having an interest in science apparently turns you into a basement-dwelling dweeb (men) or a retiring wallflower (women), as though you can only like science if you’re suffering from Asperger’s. Don’t get me wrong: I’ve known some scientists with social skills that best resemble those of a paranoid schizophrenic with anger issues, but on the whole scientists are just as human as the rest of us.
- On the other hand, scientists are not that pretty (at least, on average). Again, I’ve known some attractive scientists – both male and female – but come on. I know that Hollywood is responding to what the viewers want, which is usually “attractive flesh”, but scientist are usually shown as jaw-dropping gorgeous (or, to really shake things up, hideously unattractive – see point #1). CSI is particularly bad for this one, Grissom notwithstanding.
- Scientists don’t know everything about everything. The Stargate series, both SG-1 and Atlantis, are great examples of this. The scientific members of the team, Samantha Carter and Rodney McKay respectively, know just about everything it is possible to know. They’re both physicists by training, but in the field they magically acquire deep and broad knowledge about not only all of physics, but also chemistry, engineering, biology, etc., etc. Their range of knowledge is, frankly, ludicrous. If you know anything about modern science, you know that the amount of knowledge has exploded in the last few decades. These days, it’s increasingly hard for people to keep up with their particular corner of their own subfield of their chosen major field. There’s a reason that most of the polymaths that you hear about were active in the early 20th century or earlier…
- Not all scientists are l337 hack3rs. This one really bugs me. Being a scientist does not mean that you can find yourself plunked in front of some random computer with “encrypted data”, pound a few keys furiously, and declare “we’re in!”. Frankly, even most people who work with computers for a living can’t do this. I’ve been programming for 20 years, on and off, but I’ve never cared about security and I know that I wouldn’t be able to decrypt that terrorist hard drive just because you had to save the world.
- While we’re on the subject, computers (and technology) aren’t magic. It turns out that the mere introduction of some computers and a little lab equipment can make absolutely anything happen. I love CSI (or, really, just about any other show ever made) for this: apparently, they can blow up grainy, low-res surveillance photos to arbitrary sizes, pull details out of pixels that don’t exist, and then compare the subject’s toenails to a massive database of toenail clippings in less than half a second before generating a match.
- And another thing: where the hell do they get all that money? Just about every lab I’ve ever seen on TV or in a movie that wasn’t located in someone’s basement (and honestly, a few that were!) is dripping with beautiful, gleaming equipment that would cost millions of dollars in the real world. I wish that they could send a bit of that money our way.
- Science is all about failure and uncertainty. This is a more subtle issue, because I’m not using the words in a pejorative fashion: publish or perish aside, the driving force of science is failure and uncertainty. You try an experiment and don’t get the results you expect, so you find out why. When it turns out that you did the experiment correctly the first time and the results are still inexplicible, you get excited – something new, something you can’t explain! Your model doesn’t match realistic outcomes, so you have an excuse to build a better model. You see nature doing something that nobody expected or that nobody can explain, and it makes your year because now you have something to work on. This is the process of science, in which we chip away at the limits of our own ignorance and push back the darkness. If everything came up roses every time anyone asked a question, science as an enterprise would have been largely wrapped up in or around the 17th or 18th centuries. Yet when you look hard at scientists on TV, most of them do nothing but succeed, and when they don’t immediately have an answer, it’s cast in a negative light. Entire scientific careers can be made out of consistently asking questions to which there as (as yet) no answers, but this fact is lost on television and in the movies. Actually, it’s lost on undergrads as well, but that’s the subject of another post…
- Science is a cooperative, community effort. This is somewhat related to the issue in point number 3, where scientists are depicted as gods of knowledge, standing alone amongst the ignorant plebs. But in reality, scientists are part of a larger community working together on problems of interest. Sure, there are superstars in every field, but even they don’t stand alone: they build on the work of others, who in turn build on their work in a web of knowledgge. There’s a reason that scientists look forward to academic conferences so much; aside from the social element (which is pretty important when most of your closest intellectual colleagues are scattered across the globe), it’s a chance to connect with and immerse yourself in the cutting edge of the work being done in your field. Science isn’t advanced by the loner working in his or her basement anymore, despite what the comic books would have you believe. It’s done by a whole bunch of people, who are greater collectively than they are individually.
Those are just a few of the more egregious problems I see in the depiction of science in popular media these days. I can forgive a lot of them for the mere fact of dramatic necessity, but I worry some times that the images of science put forth are driving the public away from understanding that scientists are people doing a job, as opposed to these semi-magical beings who do things that no normal human could contemplate. The CSI effect is bad enough, but the more that we turn science into an inaccessible, mythical pursuit, the more difficult it is to recruit otherwise talented people to join us.
It’s been a while since I’ve had the chance to sit down and write another of these posts, but it’s been bugging me and so I’ve set aside some time today to try and to it justice. This time, I’m going to look at a great experimental paper from the early ’80s that shows how you can do good science by just keeping your wits about you:
D. G. C. Harper. Competitive foraging in mallards: ’ideal free’ ducks. Animal Behaviour, 30:575–584, 1982. doi:10.1016/S0003-3472(82)80071-7
An important aspect of social foraging – foraging in which the decisions of one animal hinge upon the decisions of all of the other animals in the group – is the exploitation of patchy resources. When animals are faced with multiple patches of food to choose from, how should they distribute themselves to maximize individual gain? One of the more influential models in this area has been the ideal free distribution (Fretwell and Lucas, 1969), which when stated in words goes something like this: in a situation with multiple patches of a resource (we’ll discuss food, though the idea is generalizable to other types of resources), individuals can do best by distributing themselves among the available patches according to patch profitability so that each individual’s payoff is the same. Here’s an example to clarify what I mean. Take the example of three hypothetical patches, where patch A gives out 1 food item per minute, patch B gives out 2 food items per minute, and patch C gives out 3 food items per minute. Now say that we have six ducks sitting in the middle, trying to determine how to distribute themselves so that they can maximize their individual food intake. Here’s what this would look like, hypothetically:
How do they do it? Well, if they are ideal (able to perfectly assess patch quality) and free (able to choose whatever patch they like without interference) ducks, then they would probably spread out like this:
Now, assuming that the ducks consume food at equal rates, each duck will have the maximum possible individual food intake of 1 food item per minute. A little imagination should show that any other distribution of ducks only means that some ducks are better off to switch to the above arrangement – for example, if one of the ducks from patch B found itself at patch C, then each duck there would be getting less than 1 food item per minute, and the lone remaining duck at patch B would be getting more than 1 food item per minute. In this situation, it would be a better decision for one of the four ducks at patch C to move to patch B, thus increasing their own intake rate (which has the effect of improving the intake rates of the ducks at patch C, but don’t mistake that for a group selection effect – the duck making the switch is acting solely in its own best interest).
What if individuals aren’t ideal and free? Well, let’s violate one of the assumptions and see what happens. For example, suppose that one of the ducks is a super-duck, which can fend off its fellow ducks and monopolize a patch by itself. Then the other ducks aren’t free to sort themselves in the way that would maximize their intake and would have to settle for something like this (our super-duck is (did you guess it?) red, and a little bigger too):
This is an example of the despotic model. Now the duck at patch C is able to do better by monopolizing that patch and the other five ducks have to do the best they can with the lesser resources of patches A and B.
[ Note: the above examples are assuming renewable patches, mainly because Harper’s experimental set up uses them. But the IDF would work just as well for non-renewable patches, though adjustments to the model might have to be made for handling and travel times. ]
Now, the question that Harper found himself asking was this: how do we know if animals are conforming to an ideal free distribution (IDF from here on). To know that, we have to be able to measure the payoff that each individual is receiving to see if they are all receiving an equal share. When Harper wrote the paper, nobody had managed to do this yet. Some lab experiments had been done, such as using sticklebacks in the lab as Manfred Milinski had, but Milinski hadn’t recorded the individual payoffs so there was no way to prove that the sticklebacks were using the IDF, though they did distribute themselves according to patch profitability.
To take the next step, Harper took what he had to hand and did some cool science with it. In his own words:
In my study I have been throwing pieces of bread to ducks on a garden pond and recording both the distribution of the birds between food patches and the individual food intake of some of the ducks at one of these patches (p. 575).
The paper itself contains four experiments, and though each of them is equally intriguing I don’t wish this recap of the paper to get out of hand. Therefore, I am going to describe the methodology and the first experiment, and briefly describe the rest of the results but leave the reader to view the rest of the paper. I strongly suggest that if you’re interested in this subject you read the rest of the paper.
Similar to the pictures above, Harper found a group of ducks – 33 in total, though only 24 were immediately recognizable and so they were the ones tracked – living on a lake in the Cambridge Botanic garden during the winter of 1979-80. Two observers threw pre-cut and pre-weighed bread into the water at points on the lake 20 metres apart, which were labelled site A and B. Profitability of the patch could be manipulated by changing the rate at which the bread was thrown into the water, or by changing the weight of the bread (2 or 4 grams each). The distribution of the ducks was recorded over time as the bread was thrown into the water. This allowed Harper to track the individual payoffs to each duck.
Results from Experiment 1
In experiment 1, Harper set up the site profitabilities at 50-50 so that the flock should split themselves accordingly; remembering that there were 33 ducks living on the pond, he expected that 16.5 ducks should go to each patch. Obviously, this would mean that there would be 17 ducks at one patch and 15 at another, so he recorded the mean number of ducks at each patch over multiple trials (29 in total). The results are in Figure 1 of the paper, which I’ve reproduced here:
The graph shows that the ducks did indeed sort themselves out along the lines predicted by the IDF: since the patch profitability was equal, half the ducks should have gone to patch A and half should have gone to patch B, and this is what we see from the graph. A similar picture was obtained when he manipulated the patch food ratios to be 2:1 – again, the ducks set themselves up in a 2:1 ratio. Further, as evidenced by the graph, the ducks assessed the patch profitabilities quite quickly, since equilibrium was achieved by the time that about 90 seconds had elapsed.
But is that all there is to the story? No: if you recall from above, to be an IDF, individual payoffs must be equal. That is, all the ducks must have received the same amount of bread. Did they? Harper found that the answer to this was no, they didn’t. In fact, by recording the individual payoffs he was able to determine that several of the ducks ate a disproportionate amount of food, meaning that payoffs were higher to some ducks than others. This violates one of the key IDF assumptions, and validates Harper’s criticism of previous studies; studies like the one done by Milinski on the sticklebacks seemed to show an IDF-like distribution of foragers just like the one observed here, but by recording individual payoffs Harper was able to show that the IDF behaviour was only skin-deep (as it were). In fact, the ducks’ behaviour followed that of a despotic model like the one discussed above, though unlike above it wasn’t patch access that was monopolized but food intake.
The remaining results: experiments 2, 3, and 4.
Why did some ducks eat more food than others? Harper hypothesized that dominance might be a key relation here, and in experiment 2 he was able to determine the dominance rank of the recognizeable birds and correlated it to the (heavy) skew in food intake that observed. In fact, six dominant individuals were able to monopolize up to 60% of the available food items! In experiments 3 and 4, Harper refined and tested further hypotheses on how the ducks assessed patch profitabilities and showing that the distribution of ducks was indeed sensitive to the presence of dominant ducks at a particular patch.
Why do we care?
Unlike the paper that I tackled in my first in-depth post on peer-reviewed research, this paper is less well known to the wider biological audience, though it is reasonably well-cited in foraging research. But the reason I chose to write about this paper is not that it was a famous paper, but that it is an example of good science. It identified a weakness in previous work that needed to be dealt with, and used a simple and robust methodology to thoroughly explore the issue while highlighting complex behaviour in a seemingly simple system. In doing so, it advanced our knowledge on the validity of the ideal free distribution model in real populations, in an experimental setting with good ecological validity. As the conclusion to the paper states:
The experiments described above mimic the problem that ducks face every day when being fed by the public. Except when being controlled by experimenters the rate of food item input is likely to be erratic and to be an imperfect indication of patch profitability. However it has the advantage of being detectable from a distance, and the results of experiment 4 show that other cues can be used by the ducks to correct their assessment of the patch profitability ratio. It is clear that the behaviour of ducks being fed bread on a park pond is more complicated than might be thought.
S. D. Fretwell and H. L. Lucas. On territorial behavior and other factors influencing habitat distribution in birds: I. theoretical development. Acta Biotheoretica, 19(1):1–36, 1969.