The Person and the Situation

by Lee Ross

For example, the scatterplot might portray the sociability of each member of the sixth grade in a particular elementary school measured in the lunchroom on a particular day as well as sociability measured for each child several days later on the playground. We see a great deal of variability in the amount of extroversion being manifested by the various children in each situation and a weak relationship between responses in the two situations – a relationship difficult to distinguish, at least by simple inspection, from no relationship at all (see Figure 4.1b). Obviously, a relationship as weak as this means that knowledge of any individual’s response in one situation gives us very little help in predicting that individual’s response in the other situation. To be more precise, the conventional regression formula tells us that the best predictions we could make in such circumstances would reduce our average or “standard” prediction error by only a very small amount (in fact, only about 1 percent). The reason for this is straightforward. When the outcomes being predicted are highly variable, as is the case for our sixth-graders’ displays of extroversion, the best predictions that we can make on the basis of knowledge of one previous response will, in virtually all cases, correspond to a level of extroversion very close to the average level manifested by the sixth-grade population in our study. In other words, the predictions we make generally will be similar to those we would...