How to Explain Stotting

Consider an imagined pair of black boxes with a regular pattern of signals: a caused red, and b caused green. Observers could recognize this pattern without yet interpreting what the signals meant. In each instance of button-pressing, the scientists understood exactly how each step in the computing and transmitting process worked, but they couldn't explain the generalization. You do need a semantic interpretation to explain why the regularity exists. In other words, the "macro-causal" level at which the explanation is expressed does not "reduce" to the "micro-causal" level.

Here is another instance of this very general phenomenon. You have probably seen video of gazelles being chased across the plain by a predator, and noticed that some of the gazelles are leaping high into the air during their attempts to escape their pursuer. This is called stotting. Why do gazelles stot? It is clearly beneficial, because gazelles that stot seldom get caught and eaten. This is a causal regularity that has been carefully observed, just like the regularity between buttons and lights. And it too can baffle. No account of the actions of all the proteins in all the cells of all the gazelles and the predators chasing them could reveal why this regularity exists. For that we need the branch of evolutionary theory known as costly signaling theory (Zahavi, 1987; FitzGibbon and Fanshawe, 1988). The strongest and fastest of the gazelles stot to advertise their fitness to the pursuer, signaling in effect, "Don't bother chasing me; I'm too hard to catch; concentrate on one of my cousins who isn't able to stot—a much easier meal!" and the pursuer takes this to be an honest, hard-to-fake signal and ignores the stotter. This is the free-floating rationale, and it need not be appreciated by either gazelle or predator. That is, the gazelle may be entirely oblivious to why it is a good idea to stot if it can, and the predator, say, a lion, may not understand why it finds stotting gazelles relatively unattractive prey, but if the signaling wasn't honest, costly signaling, it couldn't persist in the evolutionary arms race between predator and prey. (If evolution tried using a "cheap" signal, like tail-flicking, which every gazelle, no matter how strong or weak, could send, it wouldn't be worth it for lions to pay attention to it, so they wouldn't.) These explanations in terms of free-floating rationales are not reducible to explanations at lower levels, such as the molecular level, but it is important to recognize that even though the explanation of why and how stotting works is from the intentional stance (in terms of what it would be rational for a lion to conclude from the stotting of the gazelle), the individual lion or gazelle need not understand the meaning of stotting for it to work; they need only sorta understand it.