Several years ago, I got to be one of the grown-ups overseeing an elementary school field day at a park. The kids were having lunch, and I was at a picnic table with three fifth graders. Here is part of the conversation at the table.
Allen: Wanna hear a joke? Forest: Sure! Alan: I’m so glad I hate broccoli! You know why? Kenon: Why? Alan: Because if I liked broccoli, I would eat it. And I hate to eat things that taste awful! Get it? Do you get it? I chuckled. Forest shrugged, and Kenon rolled his eyes. Alan proceeded to try to explain his joke to his unamused classmates. Alan: See? If I liked it, it wouldn’t taste awful! Get it?
I don’t think the other two fifth graders saw the internal contradiction that made this joke funny to Alan (although Kenan may have understood the contradiction without judging it as funny). Take a look at three impressive features of the reasoning required and the psychological and philosophical questions raised by Alan’s joke.
Counterfactual Thinking
The joke hinges on the mastery of counterfactual reasoning. Alan claims to hate broccoli, but he has the power to imagine a world in which he likes it. Piaget proposed that we come to reason about hypothetical and abstract realities at the cusp of puberty. Still, English-speaking college students, when they study a second language, regularly struggle with the subjunctive case: “if I were to like broccoli”, and there are many examples of adults who don’t seem to have mastered the counterfactual. On the third hand, subjunctive thinking is surely what allows us to enjoy fiction and to take flights of imagination. Jerome Bruner, in Actual Minds Possible Worlds proposed that the ability to enter pretend worlds is ‘built-in’ for humans and emerges very early in childhood.
Propositional Logic
Try to take yourself back to whatever class introduced you to propositional logic, and look at the structure of Alan’s joke.
Let p = I hate broccoli and not p = I like broccoli.
Let q = awful taste and not q = good taste.
Consider the proposition, “If I hate broccoli, then broccoli tastes awful.” (if p then q)
Which of the following observations would invalidate this proposition?
I hate broccoli, and it tastes awful (p co-occurs with q) I hate broccoli, and it tastes good (p co-occurs with not q) I like broccoli, and it tastes good (not-p co-occurs with not q) I like broccoli, and it tastes awful (not p co-occurs with q)
Before you learned propositional logic, you may have imagined that both the second and the fourth observations would invalidate the proposition. Your logic or rhetoric teacher, or your debate coach should have convinced you that both not-p observations are irrelevant to the validation of ‘if p then q’.
“I like broccoli, and it tastes bad,” is a logical possibility, given the way Alan’s joke is set up. It is, however, a psychological absurdity. There are many ways in which the propositional logic of intro philosophy solves problems differently than the natural language logic studied by cognitive psychologists. This clash between propositional logic and natural language reasoning is partly responsible for the opacity of most legal documents. It may also be responsible for the humor in Alan’s joke.
Linguistic Subjectivity
There is another very sophisticated psycholinguistic problem that Alan’s joke calls up. When we say, “broccoli tastes bad”, we have located the bad taste in the broccoli. (Broccoli is the grammatical subject of the sentence, even though the broccoli does not do the tasting.) When we say, “I hate broccoli,” we have located the bad taste in the self, which is the grammatical subject of the sentence. This is a linguistic subtlety that can have enormous social and psychological consequences. (Think about the difference between “You are an annoying child” and “I am annoyed by you.”)
Children (and probably grown-ups as well) find things amusing when they are just on the cusp of understanding them. It may be that Alan was just beginning to understand counterfactual reasoning. (Cognitive scientists expect this to emerge at around age 12.) He may have been on the verge of recognizing that formal logic and psychological logic sometimes clash (a much more sophisticated recognition that baffles college students.) It may be that he was just starting to think about the difference between claiming or obscuring subjectivity in linguistic expressions (something that started to fascinate me in graduate school.) I have occasionally been accused of attributing too much sophistication to children’s thinking, so today I am going to propose that the first of these three possibilities is most likely. However, the more I listen to children, the more wisdom and perceptiveness I see in their questions and observations of the world. Alan may well be a budding logician or psycholinguist.
It is delightful to watch what makes children laugh, even if you don’t analyze the humor right out of it, as I have done above. It is, however, also fascinating to think about why they are amused. As I argued in a post back in February, we can get a glimpse of what children are currently trying to understand about the world when we try to understand their take on what is funny.
I think there may be a few philosophers, several psychologists, a couple of mathematicians, and one or two linguists among the readers of Listening to Children. I’m curious about whether you find Alan’s joke even mildly amusing, and about whether you remember a time in your own childhood when this joke would have been funny to you. What do you think of my speculations about Alan’s thinking? Click the ‘comment’ button below, please, and let me know!