Red Mars (Mars Trilogy, #1) - Kim Stanley Robinson Page 0,101

was a doctor in a hospice in a prison in hell; and the doctor was sick.

He hadn’t been able to adapt. People were different in that regard, it was a matter of temperament. Maya, walking toward the lock door, had a temperament quite different from his, which somehow enabled her to be completely at home here. To tell the truth he didn’t think she really noticed her surroundings much in any case. And yet in other ways he and she were similar. It had to do with the lability-stability index, and its particular emotionality; they were both labile. And yet fundamentally they were very different characters; the labile-stabile index had to be considered in combination with the very different set of characteristics grouped under the labels extroversion and introversion. This had been his great discovery of the recent year, and now it structured all his thinking about himself and his charges.

Walking toward the Alchemists’ Quarter, he fit the morning’s events into the gridwork of this new characterological system. Extroversion-introversion was one of the best-studied systems of traits in all psychological theory, with great masses of evidence from many different cultures supporting the objective reality of the concept. Not as a simple duality of course; one did not label a person plainly this or that, but rather placed them on a scale, rating them for such qualities as sociability, impulsiveness, changeability, talkativeness, outgoingness, activity, liveliness, excitability, optimism, and so on. These measurements had been done so many times that it was statistically certain that the various traits did indeed hang together, to a degree that exceeded chance by a huge amount. So the concept was real, quite real! In fact physiological investigations had revealed that extroversion was linked with resting states of low cortical arousal, introversion with high cortical arousal; this had sounded backward to Michel at first, but then he remembered that the cortex inhibits the lower centers of the brain, so that low cortical arousal allows the more uninhibited behavior of the extrovert, while high cortical arousal is inhibitory and leads to introversion. This explained why drinking alcohol, a depressant which lowers cortical arousal, could lead to more excited and uninhibited behavior.

So the whole collection of extrovert-introvert traits, with all that they said about one’s character, could be traced back to a group of cells in the brain stem called the ascending reticular activating system, the area that ultimately determined levels of cortical arousal. Thus they were driven by biology. There should be no such thing as fate: Ralph Waldo Emerson, a year after his six-year-old son died. But biology was fate.

And there was more to Michel’s system; fate, after all, was no simple either/or. He had recently begun to consider Wenger’s index of autonomic balance, which used seven different variables to determine whether an individual was dominated by the sympathetic or the parasympathetic branches of the autonomic nervous system. The sympathetic branch responds to outside stimuli and alerts the organism to action, so that individuals dominated by this branch were excitable; the parasympathetic branch, on the other hand, habituates the alerted organism to the stimulus, and restores it to homeostatic balance, so that individuals dominated by this branch were placid. Duffy had suggested calling these two classes of individuals labiles and stabiles, and this classification, while not as famous as extroversion and introversion, was just as solidly backed by empirical evidence, and just as useful in understanding varieties of temperament.

Now, neither system of classification told the investigator all that much about the total nature of the personality being studied. The terms were so general, they were collections of so many traits, that they said very little in any useful diagnostic sense, especially since both were Gaussian curves in the actual population.

But combine the two systems, and it began to get very interesting indeed.

It was not a simple matter, and Michel had spent a fair amount of time at his computer screen sketching one kind of combinatoire after another, using the two different systems as the x and y axes of several different grids, none of which told him much. But then he began moving the four terms around the initial points of a Greimas semantic rectangle, a structuralist schema with alchemical ancestry, which proposed that no simple dialectic was enough to indicate the true complexity of any cluster of related concepts, so that it was necessary to acknowledge the real difference between something’s opposite and its contrary; the concept “not-X” being not quite the same thing as “anti-X,”