Why Spock is Not Rational

Star Trek’s Mr. Spock is not the exemplar of logic and rationality you might think him to be. Instead, he is a “straw man” of rationality used to show (incorrectly) that human emotion and irrationality are better than logic.

Here is a typical scene:

McCoy: Well, Mr. Spock, [the aliens] didn’t stay frightened very long, did they? Spock: A most illogical reaction. When we demonstrated our superior weapons, they should have fled. McCoy: You mean they should have respected us? Spock: Of course! McCoy: Mr. Spock, respect is a rational process. Did it ever occur to you that they might react emotionally, with anger? Spock: Doctor, I’m not responsible for their unpredictability. McCoy: They were perfectly predictable, to anyone with feeling! You might as well admit it, Mr. Spock: your precious logic brought them down on us!1

Of course, there’s nothing logical about expecting non-logical beings to act logically. Spock had plenty of evidence that these aliens were emotional, so expecting them to behave rationally was downright irrational!

I stole this example from Julia Galef’s talk “The Straw Vulcan.”2 Her second example of “straw man rationality,” or Hollywood Rationality, is the idea that you shouldn’t make a decision until you have all the information you need. This one shows up in Star Trek too. A giant space amoeba has appeared not far from the Enterprise, and Kirk asks Spock for his analysis. Spock replies, “I have no analysis due to insufficient information . . . The computers contain nothing on this phenomenon. It is beyond our experience, and the new information is not yet significant.”3

Sometimes it’s rational to seek more information before acting, but sometimes you need to just act on what you think you know. You have to weigh the cost of getting more information against the expected value of that information. Consider another example from Gerd Gigerenzer, about a man considering whom to marry:

He would have to look at the probabilities of various consequences of marrying each of them—whether the woman would still talk to him after they’re married, whether she’d take care of their children, whatever is important to him—and the utilities of each of these. . . . After many years of research he’d probably find out that his final choice had already married another person who didn’t do these computations, and actually just fell in love with her.4

Such behavior is irrational, a failure to make the correct value of information calculation.

Galef’s third example of Hollywood Rationality is the mistaken principle that “being rational means never relying on intuition.” For example, in one episode of Star Trek, Kirk and Spock are playing three-dimensional chess. When Kirk checkmates Spock, Spock says, “Your illogical approach to chess does have its advantages on occasion, Captain.”5

But something that causes you to win at chess can’t be irrational (from the perspective of winning at chess). If some method will cause you to win at chess, that’s the method a rational person would use. If intuition will give you better results than slow, deliberative reasoning, then rationally you should use intuition. And sometimes that’s the case, for example if you have developed good chess intuitions over thousands of games and you’re playing speed chess that won’t permit you to think through the implications of every possible move using deliberative reasoning.

Galef’s fourth principle of Hollywood Rationality is that “being rational means [not having] emotions.”

To be sure, emotions often ruin our attempts at rational thought and decision-making. When we’re anxious, we overestimate risks. When we feel vulnerable, we’re more likely to believe superstitions and conspiracy theories. But that doesn’t mean a rational person should try to destroy all their emotions. Emotions are what create many of our goals, and they can sometimes help us to achieve our goals, too. If you want to go for a run and burn some fat, and you know that listening to high-energy music puts you in an excited emotional state that makes you more likely to go for a run, then the rational thing to do is put on some high-energy music.

Rationality done right is “systematized winning.” Epistemic rationality is about having the most probably true beliefs, and instrumental rationality is about making decisions that maximize your chances of getting the most of what you want. So, as Galef says,

If you think you’re acting rationally, but you keep getting the wrong answer, and you keep ending up worse off than you could be, then the conclusion that you should draw from that is not that rationality is bad. It’s that you’re being bad at rationality.6

I’ll return to the subject of the intelligence explosion shortly, but I want to spend two more chapters on rationality. There are laws of thought, and we need to agree on what they are before we start talking about tricky subjects like AI. Otherwise we’ll get stalled on a factual disagreement only to later discover that we’re really stalled because we disagree about how we can come to know which facts are correct.

1Oliver Crawford, “The Galileo Seven,” Star Trek: The Original Series, season 1, episode 13, dir. Robert Gist, aired January 5, 1967 (CBS).

2Julia Galef, “The Straw Vulcan: Hollywood’s Illogical Approach to Logical Decisionmaking,” Measure of Doubt (blog), November 26, 2011, accessed November 10, 2012, http://measureofdoubt.com/2011/11/26/the-straw-vulcan-hollywoods-illogical-approach-to-logical-decisionmaking/.

3Robert Sabaroff, “The Immunity Syndrome,” Star Trek: The Original Series, season 2, episode 19, dir. Joseph Pevney, aired January 19, 1968 (CBS).

4Gerd Gigerenzer, “Smart Heuristics,” Edge, March 29, 2003, http://edge.org/conversation/smart-heuristics-gerd-gigerenzer.

5D. C. Fontana, “Charlie X,” Star Trek: The Original Series, season 1, episode 7, dir. Lawrence Dobkin, aired September 15, 1966 (CBS).

6Galef, “The Straw Vulcan,” italics added.

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