"This ability to form and then to drop, or lower to the level of acquaintanceship, close relationships quickly, coupled with increased mobility, will result in any given individual forming many more friendships than is possible for most in the present ... Friendship patterns of the majority in the future will provide for many satisfactions, while substituting many close relationships of shorter durability for the few long-term friendships formed in the past."

One reason to believe that the trend toward temporary relationships will continue is the impact of new technology on occupations. Even if the push toward megalopolis stopped and people froze in their geographical tracks, there would still be a sharp increase in the number, and decrease in the duration of relationships as a consequence of job changes. For the introduction of advanced technology, whether we call it automation or not, is necessarily accompanied by drastic changes in the types of skills and personalities required by the economy.

Specialization increases the number of different occupations. At the same time, technological innovation reduces the life expectancy of any given occupation. "The emergence and decline of occupations will be so rapid," says economist Norman Anon, an expert in manpower problems, "that people will always be uncertain in them." The profession of airline flight engineer, he notes, emerged and then began to die out within a brief period of fifteen years.

A look at the "help wanted" pages of any major newspaper brings home the fact that new occupations are increasing at a mind-dazzling rate. Systems analyst, console operator, coder, tape librarian, tape handler, are only a few of those connected with computer operations. Information retrieval, optical scanning, thin-film technology all require new kinds of expertise, while old occupations lose importance or vanish altogether. When Fortune magazine in the mid-1960's surveyed 1,003 young executives employed by major American corporations, it found that fully one out of three held a job that simply had not existed until he stepped into it. Another large group held positions that had been filled by only one incumbent before them. Even when the name of the occupation stays the same, the content of the work is frequently transformed, and the people filling the jobs change.

Job turnover, however, is not merely a direct consequence of technological change. It also reflects the mergers and acquisitions that occur as industries everywhere frantically organize and reorganize themselves to adapt to the fast-changing environment, to keep up with myriad shifts in consumer preferences. Many other complex pressures also combine to stir the occupational mix incessantly. Thus a recent survey by the US Department of Labor revealed that the 71,000,000 persons in the American labor force had held their current jobs an average of 4.2 years. This compared with 4.6 years only three years earlier, a decline in duration of nearly 9 percent.

"Under conditions prevailing at the beginning of the 1960's," states another Labor Department report, "the average twenty-year-old man in the work force could be expected to change jobs about six or seven times." Thus instead of thinking in terms of a "career" the citizen of super-industrial society will think in terms of "serial careers."

Today, for manpower accounting purposes, men are classified according to their present jobs. A worker is a "machine operator" or a "sales clerk" or a "computer programmer." This system, born in a less dynamic period, is no longer adequate, according to many manpower experts. Efforts are now being made to characterize each worker not merely in terms of the present job held, but in terms of the particular "trajectory" that his career has followed. Each man's trajectory or career line will differ, but certain types of trajectories will recur. When asked "What do you do?" the super-industrial man will label himself not in terms of his present (transient) job, but in terms of his trajectory type, the overall pattern of his work life. Such labels are more appropriate to the super-industrial job market than the static descriptions used at present, which take no account of what the individual has done in the past, or of what he may be qualified to do in the future.

The high rate of job turnover now evident in the United States is also increasingly characteristic of Western European countries. In England, turnover in manufacturing industries runs an estimated 30 to 40 percent per year. In France about 20 percent of the total labor force is involved in job changes each year, and this figure, according to Monique Viot, is on the rise. In Sweden, according to Olof Gustafsson, director of the Swedish Manufacturing Association, "we count on an average turnover of 25 to 30 percent per year in the labor force ... Probably the labor turnover in many places now reaches 35 to 40 percent."

Whether or not the statistically measurable rate of job turnover is rising, however, makes little difference, for the measurable changes are only part of the story. The statistics take no account of changes of job within the same company or plant, or shifts from one department to another. A. K. Rice of the Tavistock Institute in London asserts that "Transfers from one department to another would appear to have the effect of the beginning of a 'new life' within the factory." The overall statistics on job turnover, by failing to take such changes into account, seriously underestimate the amount of shifting around that is actually taking place – each shift bringing with it the termination of old, and the initiation of new, human relationships.

Any change in job entails a certain amount of stress. The individual must strip himself of old habits, old ways of coping, and learn new ways of doing things. Even when the work task itself is similar, the environment in which it takes place is different. And just as is the case with moving to a new community, the newcomer is under pressure to form new relationships at high speed. Here, too, the process is accelerated by people who play the role of informal integrator. Here, too, the individual seeks out human relationships by joining organizations – usually informal and clique-like, rather than part of the company's table of organization. Here, too, the knowledge that no job is truly "permanent" means that the relationships formed are conditional, modular and, by most definitions, temporary.

In our discussion of geographical mobility we found that some individuals and groups are more mobile than others. With respect to occupational mobility, too, we find that some individuals or groups make more job changes than others. In a very crude sense, it is fair to say that people who are geographically mobile are quite likely to be occupationally mobile as well. Thus we once more find high turnover rates among some of the least affluent, least skilled groups in society. Exposed to the worst shocks and buffetings of an economy that demands educated, increasingly skilled workers, the poor bounce from job to job like a pinball between bumpers. They are the last hired and the first fired.

Throughout the middle range of education and affluence, we find people who, while certainly more mobile than agricultural populations, are nonetheless, relatively stable. And then, just as before, we find inordinately high and rising rates of turnover among those groups most characteristic of the future – the scientists and engineers, the highly educated professionals and technicians, the executives and managers.

Thus a recent study reveals that job turnover rates for scientists and engineers in the research and development industry in the United States are approximately twice as high as for the rest of American industry. The reason is easy to detect. This is precisely the speartip of technological change – the point at which the obsolescence of knowledge is most rapid. At Westinghouse, for example, it is believed that the so-called "half-life" of a graduate engineer is only ten years – meaning that fully one half of what he has learned will be outdated within a decade.