Next, an attempt is made to explain the roughly uniform distribution of prestige as between the major types of positions in every society. Because, however, there occur between one society and another great differences in the degree and kind of stratification, some attention is also given to the varieties of social inequality and the variable factors that give rise to them ....
Throughout, it will be necessary to keep in mind one thing-namely, that the discussion relates to the system of positions, not to the individuals occupying those positions. It is one thing to ask why different positions carry different degrees of prestige, and quite another to ask how certain individuals get into those positions. Although, as the argument will try to show, both questions are related, it is essential to keep them separate in our thinking.
The main functional necessity explaining the universal presence of stratification is precisely the requirement faced by any society of placing and motivating individuals in the social structure. As a functioning mechanism a society must somehow distribute its members in social positions and induce them to perform the duties of these positions. It must thus concern itself with motivation at two different levels: to instill in the proper individuals the desire to fill certain positions, and, once in these positions, the desire to perform the duties attached to them.
One may ask what kind of rewards a society has at its disposal in distributing its personnel and securing essential services. It has, first of all, the things that contribute to sustenance and comfort. It has, second, the things that contribute to humor and diversion. And it has, finally, the things that contribute to self-respect and ego expansion. The last, because of the peculiarly social character of the self, is largely a function of the opinion of others, but it nonetheless ranks in importance with the first two. In any social system all three kinds of rewards must be dispensed differentially according to positions.
Granting the general function that inequality subserves, one can specify the two factors that determine the relative rank of different positions. In general those positions convey the best reward, and hence have the highest rank, that (a) have the greatest importance for the society and (b) require the great training or talent. The first factor concerns function and is a matter of relative significance; the second concerns means and is a matter of scarcity.
Actually a society does not need to reward positions in proportion to their functional importance. It merely needs to give sufficient reward to them to insure that they will be filled competently. In other words, it must see that less essential positions do not compete successfully with more essential ones. If a position is easily filled, it need not be heavily rewarded, even though important. On the other hand, if it is important but hard to fill, the reward must be high enough to get it filled anyway. Functional importance is therefore a necessary but not a sufficient cause of high rank being assigned to a position.
Practically all positions, no matter how acquired, require some form of skill or capacity for performance. There are, ultimately, only two ways in which a person's qualifications come about: through inherent capacity or through training. Obviously, in concrete activities both are always necessary, but from a practical standpoint the scarcity may lie primarily in one or the other, as well as in both.
Insofar as there is a difference between one system of stratification and another, it is attributable to whatever factors affect the two determinants of differential reward-namely, functional importance and scarcity of personnel.