...responding to the player's own body language rather than mathematical rules.

I've done a lot of machine learning. It's very much mathematical rules. The inferred rules just happen to be so complicated that it's often hard to recognize them as such.

Maybe the submitter meant "hand-crafted decision tree".

It's because it's a calculus: a method of calculating things. In this case, the things are higher-order functions, and the method is beta-reduction.

Your other points are well-taken, however.

My problem with the question and all the answers so far is that they are focusing on generalities. It's true that most programmers won't need calculus. However, we desperately need the 2% that do, because scientists from other fields don't get taught how to program. Oh, they pick it up on the job. They have to take one programming course from the CS department. But they rarely get rigorous training in software engineering that they need to make reliable stuff.

If there are environmental factors, they're slight. It's as heritable as height.

Plenty of things can cause the same symptoms in the short term without the neurological condition. Examples are the death of a parent (the emotional pain is, among other things, highly distracting), lack of sleep, and malnutrition. Yes, staring at a screen all day and experiencing nothing but rapid, small rewards can cause an otherwise healthy kid to find other things less rewarding. But I've read a lot about ADHD, and I've never seen anything conclusive that says such things can give a child the actual disorder.

I'm an extrovert, and I had that same reaction to the article. Ha ha.

Um, I do understand introverts pretty well, though. I think I've boiled the essence of the difference between extroverts and introverts down to cost. For an extrovert, the cost of speaking is either negative (your "spewing drivel all the time" kind) or zero (your "thinking out loud all the time" kind). For an introvert, the cost is positive, and sometimes very high. Introverts spend a lot of time determining either 1) the best way to say something, to minimize the cost of saying it overall, or 2) whether it's worth saying anything in the first place.

I'm convinced we need both kinds of people. Here's an example from one context. I once taught an entire class of introverts. It was horrendous. Nobody talked. I never got in-class feedback so that I could adjust the presentation on-the-fly. (I've since learned that partitioning the class into small groups can help. It lowers the cost of speaking.) I've also taught an entire class of extroverts. It was likewise horrendous. Everybody talked. We never got anywhere in the material. I've mostly taught classes with a mix of students, and that seems to work out the best. I get immediate feedback from the extroverts, and more thoughtful feedback from the introverts when they come to me for private help.

The thing I appreciate most about introverts is that I can count on something thoughtful from them, and I've learned to wait for it.

Bah. This is human nature, not just Americans.

Each of our states is as big as a country. How many Europeans could name the states surrounding the one I live in? Not many.

In this country, a Texan is as close to a foreigner as most people are likely to meet.

When I lived in Scotland, I was asked at least twice a month whether I knew Pamela Anderson. (No, by the way.) The kids there had no idea just how big this place is. Friggin' huge, is what it is. Like Sputnik.

Don't forget that we don't just use our space for candy. There's also Unicode, which is often done with 32-bit characters, so 4x on your strings right there. Along with that is internationalization, so your strings get duplicated 10x or whatever. Further, every 64-bit pointer takes 4x the space of a 16-bit pointer. We also use a LOT more pointers, because we have this crazy, correct idea that fixed-length data structures are evil in multiple ways. We also tend to write in imperative object-oriented or quasi-pure functional style, which are both a bit bloaty, because with those styles it's a lot easier to write extensible code. (With OO, it's easier to extend the kinds of objects on the system; with functional, easier to extend the kinds of operations.)

So yeah, it's not just candy or foregoing optimization. We've been moving toward making it easy for every programmer, regardless of skill, to write code that, if not correct, will at least not blow up your computer, and do a lot of really cool stuff.