With the spread of education and the general enhancement of the sense of personal selfhood and individuality among large numbers of people, the demand for privacy has increased. The modern reader is shocked to discover in the literature of the Elizabethan period the amazing lack of a sense of privacy there exhibited. In contemporary society this sense and the possibility of its satisfaction are variously displayed on different economic and social levels. In the congested life of the tenements it is almost impossible, and many social evils are to be traced to the promiscuous mingling of large families (and sometimes additional boarders) in congested quarters.
The demand for privacy and solitude becomes acute among people who do a great deal of mental work. "Man," says Nietzsche, "cannot think in a herd," and the thinker has traditionally been pictured as a solitary man. This is because quiet seems to be, for most men, an essential condition of really creative thought. There are some men who find it impossible to write when there is another person, even one of whom they are fond, in the same room. "No man," writes Mr. Graham Wallas, "is likely to produce creative thoughts (either consciously or subconsciously) if he is constantly interrupted by irregular noises." Constant association with other people means, moreover, continual distraction by conversation which seriously interrupts a consecutive train of thought. The insistence in public and college reading rooms on absolute quiet is a device for securing as nearly as may be privacy in intellectual work.
Privacy is again demanded as a matter of emotional protection in individuals in whom there is a highly sensitive development of personal selfhood. We like to keep our concerns to ourselves, or to share them only with those with whom we have a marked community of interest and feeling. Children love to "have secrets they won't tell," and older people, especially sensitive and intelligent ones, feel a peculiar sense of irritation at having their personal affairs and feelings publicly displayed. Nearly everyone must recall occasions where he was vividly communicative and loquacious with a friend, only to relapse into a clam-like silence on the entry of a third person. This is primarily due to the fact that while men are by nature gregarious, their gregariousness early becomes specialized and aroused exclusively by people for whom they develop a sense of personal affection and common sympathy. Any intrusion from without this circle becomes an intrusion upon privacy.