A couple of weeks ago, I was standing in the kitchen when my partner came home in the evening. There was a glass half-full with a black-brown-ish liquid standing on the kitchen counter, and this glass was the first thing his gaze fell upon when he entered the room.
“What is that?” he asked.
“What do you think it is?” I replied, at which he stared at the glass for a few more seconds. He was standing some distance away from the glass, and so couldn’t deduce the exact nature of its content merely from a glance.
“It’s either coffee or coca cola.”
I didn’t say anything, hoping that he would reason aloud about whether it was coffee or coca cola – which he, in fact, went on to do. And in the most adorable way, too. He gave me an excited smile and said,
“I will use the deduction and reasoning techniques that you – and Eliezer Yudkowsky – have taught me!”
Jackpot. This would be fun. I enjoy learning about rationality, and I love sharing it all with him – it would be interesting to see what he had learned. He started by saying,
“We didn’t have any coca cola when I left home this morning. We did have instant coffee, though.”
“I could have gone and bought some coca cola,” I responded matter-of-factly.
“True,” he allowed, “but considering that you really dislike leaving the apartment if you don’t have an important errand, it’s not very likely. And I doubt that you would go out just to buy some coca cola, especially seeing that we’re both trying to consume less sugar.”
“It could be sugarfree.”
“Yes… But still, I find it more likely that you would make some instant coffee.”
“Without milk? You know I hate coffee without milk. And why would I use a glass instead of a cup?”
This confused him for a moment. “You’re right. That seems really odd…” But then he seemed to come up with a new theory. “We’re probably out of milk. Maybe you just wanted a quick energy boost, but you realised that we don’t have any milk, and so you thought that you would take a small glass instead of a cup, so that you could drink the coffee like a kind of energy shot, without tasting the bitter coffee too much.”
I opened the fridge so that he could see that we were indeed out of milk. But, when he seemed to think that he had figured it all out, I countered with, “This isn’t the end just yet – why is the liquid not hot, if it’s coffee? As you can see, there is no vapour.”
“Ah, that’s easy. You didn’t succeed in making it drinkable – you found it disgusting without milk, which is why you only drank half of it. Then you left the glass here on the counter. It’s probably been standing there for a while now, cooling.”
I tried to keep my pokerface on as lifted up the glass and presented it to him. “Pinch your nose and drink it,” I told him. And so he pinched his nose, drank some of the dark liquid, and then removed his fingers. As the taste spread to his taste buds, he started grinning.
“I was right.”
“You were,” I said, grinning with him.
Conclusion: Rationality isn’t just useful, it’s fun too.
(Bonus Conclusion: I should probably go out more.)
Need For Cognition 