In line with Marcus’s Monday Meslier.
Bees seem to understand the idea of zero – the first invertebrate shown to do so. When the insects were encouraged to fly towards a platform carrying fewer shapes than another one, they apparently recognised “no shapes” as a smaller value than “some shapes”.
Zero is not an easy concept to comprehend, even for us. Young children learn the number zero later than other numbers, and often have trouble identifying whether it is less than or more than 1.
Apart from ourselves, some other animals grasp the concept of zero, though. Chimpanzees and monkeys, for instance, have been able to consider zero as a quantity when taught.
With their tiny brains, bees may seem an unlikely candidate to join the zero club. But they have surprisingly well-developed number skills: a previous study found that they can count to 4.
To see whether honeybees are able to understand zero, Scarlett Howard at RMIT University in Melbourne and her colleagues first trained bees to differentiate between two numbers. They set up two platforms, each with between one and four shapes on it.
On one platform, bees were given a sweet sucrose solution, and on the other a nasty-tasting quinine solution. Previous research has found that bees learn more quickly if they are not merely rewarded for correct choices, but also punished for wrong ones.
The researchers trained the bees to associate a platform that had fewer shapes on it with the sweet reward, until they made the right choice 80 per cent of the time. The bees were put through further tests with differently shaped objects to confirm that they were responding to the number of shapes and not their appearance.
Next, when given a choice between two or three shapes and “zero” shapes, bees picked zero most of the time.
Marcus Ranum says
That is awesome! I’m surprised if octopi don’t also. But maybe ‘zero’ isn’t useful to them because they don’t collectively harvest stuff. Crows can do basic remainder/division and they collectively harvest stuff (I got a great demonstration of that the other day when I threw a bag of stale corn chips out into the yard)
Cool! I wish crows would surface to my feeding stations, but they stay well away from humans here.
The camels are not impressed.
But then again, not much impresses a camel. Euclid, Euler, Einstein, Escher, Archimedes, Gödel, and Bach, perhaps…
consciousness razor says
The articles goes on….
It sounds like what’s going on is that the bees are simply conditioned to avoid these shapes. Fewer shapes on a platform (including of course zero of them) means there will be less of a visual stimulus for the bees to use when deciding where they will go and what they will try to avoid. I wouldn’t say they need a concept of numbers just to do that. It would be interesting if a mathematician or a philosopher of mathematics weighed in on here (not just biologists), but I find it hard to believe they could find good, solid, non-bullshitty reasons to endorse claims like that.
The stimuli themselves have a certain structure which can be represented mathematically (the presence of different numbers of objects in various locations), and the bees simply respond to those. You see a scary-looking thing (or a disgusting one, etc.) and you’ll probably go the other way — no surprises here. They don’t need to have such concepts or do any abstract mathematical reasoning for that. The “numerical distance” discussed above isn’t a math problem the bees are solving in their little heads — it’s representing the strength of the signal (“avoid this thing which has quinine”) that experimentalists created for the bees. That’s literally what is going on. It probably won’t attract much attention or generate many fantastical headlines, if you put that in your press release, try to get more funding for your next paper, etc., but there you have it.
So this doesn’t look like serious evidence that bees have concepts of numbers, or specifically a concept of zero. What I would expect if they weren’t conceiving of numbers is exactly the same: they’ll have a harder time when the signal is less strong (when only one shape is there) compared to when it is stronger (when there are a larger number of shapes, all associated with avoiding such platforms). And when there is no signal (zero shapes), of course that’s giving the bees less stimuli to work with than it would have if it were any positive number. But bees don’t need to understand that, do arithmetic, reason about why mathematically zero is less than one and the difference is even greater for larger positive numbers, etc. Experimenters just need to understand that kind of stuff when they design their experiments.
By the same reasoning, you could claim plants “know” or “understand” the difference between zero sun (in a dark room and no photosynthesis), some fraction of the sun’s output in standard atmospheric conditions (if it’s partly shaded, for example), a whole sun in those conditions, or even some very complicated set of equations describing varying light levels, which are then associated with what the plants do as a consequence. You could claim they have a concept not just of “zero” sun, but also fractions, real numbers, differential equations … all sorts of wacky claims are open for you here, if you’re really interested in anthropomorphizing plants. But in fact, they don’t know anything about that, nor do they even have brains to do any kind of thinking. That’s all explained perfectly well, just by the fact that they respond differently to different stimuli. Although bees are processing visual cues and so forth, I don’t see what relevant factors are supposed to make the situation here any different.