We psychologists all too often do the same thing today, albeit in a more sophisticated form. Consider, for example, the procedure described in Chapter 5 for mapping a person's location in experiential space. Suppose that in the course of an experiment we measure two variables, X and Y, in a group of subjects. If we distrust such great abstraction of the data, we can ask the computer to print out a scatter plot of the raw data, the actual position of each subject instead of the abstraction for all subjects. The straight road is somewhat broad, but still basically straight.
More imagery goes with more analgesia.
Suppose, however, that we actually go back to our subjects and test some of them repeatedly, obtain samples over time, an experiential mapping, of their simultaneous abilities to experience analgesia and imagery. Then we find that our subjects actually fall into three distinct types, as shown in the upper charts of Figure 9-1. Type A shows either a low degree of both analgesia and imagery or a fair degree of analgesia and imagery, but no other combinations. Type B shows a low to fair degree of analgesia and imagery or a very high degree of analgesia and imagery, but no other combinations. Type C shows a high variability of degree of analgesia and imagery, a much wider range of combinations.