To understand why acceleration in the pace of life may prove disruptive and uncomfortable, it is important to grasp the idea of "durational expectancies."

Man's perception of time is closely linked with his internal rhythms. But his responses to time are culturally conditioned. Part of this conditioning consists of building up within the child a series of expectations about the duration of events, processes or relationships. Indeed, one of the most important forms of knowledge that we impart to a child is a knowledge of how long things last. This knowledge is taught, in subtle, informal and often unconscious ways. Yet without a rich set of socially appropriate durational expectancies, no individual could function successfully.

From infancy on the child learns, for example, that when Daddy leaves for work in the morning, it means that he will not return for many hours. (If he does, something is wrong; the schedule is askew. The child senses this. Even the family dog – having also learned a set of durational expectancies – is aware of the break in routine.) The child soon learns that "mealtime" is neither a one-minute nor a five-hour affair, but that it ordinarily lasts from fifteen minutes to an hour. He learns that going to a movie lasts two to four hours, but that a visit with the pediatrician seldom lasts more than one. He learns that the school day ordinarily lasts six hours. He learns that a relationship with a teacher ordinarily extends over a school year, but that his relationship with his grandparents is supposed to be of much longer duration. Indeed, some relationships are supposed to last a lifetime. In adult behavior, virtually all we do, from mailing an envelope to making love, is premised upon certain spoken or unspoken assumptions about duration.

It is these durational expectancies, different in each society but learned early and deeply ingrained, that are shaken up when the pace of life is altered.

This explains a crucial difference between those who suffer acutely from the accelerated pace of life and those who seem rather to thrive on it. Unless an individual has adjusted his durational expectancies to take account of continuing acceleration, he is likely to suppose that two situations, similar in other respects, will also be similar in duration. Yet the accelerative thrust implies that at least certain kinds of situations will be compressed in time.

The individual who has internalized the principle of acceleration – who understands in his bones as well as his brain that things are moving faster in the world around him – makes an automatic, unconscious compensation for the compression of time. Anticipating that situations will endure less long, he is less frequently caught off guard and jolted than the person whose durational expectancies are frozen, the person who does not routinely anticipate a frequent shortening in the duration of situations.

In short, the pace of life must be regarded as something more than a colloquial phrase, a source of jokes, sighs, complaints or ethnic put-downs. It is a crucially important psychological variable that has been all but ignored. During past eras, when change in the outer society was slow, men could, and did, remain unaware of this variable. Throughout one's entire lifetime the pace might vary little. The accelerative thrust, however, alters this drastically. For it is precisely through a step-up in the pace of life that the increased speed of broad scientific, technological and social change makes itself felt in the life of the individual. A great deal of human behavior is motivated by attraction or antagonism toward the pace of life enforced on the individual by the society or group within which he is embedded. Failure to grasp this principle lies behind the dangerous incapacity of education and psychology to prepare people for fruitful roles in a super-industrial society.