单项选择题

The deterioration of the environment, both physically and aesthetically, is most apparent in our cities. The dehumanizing effects of life in the slums and ghettoes particularly, where there is little hope for improving conditions, have often been cited as contributing causes of urban rioting and disturbances. Crime rates usually reach their peak in these neighborhoods. Such symptoms of general psychological maladjustment suggest that modern cities provide a less than ideal environment for human beings.
There seems to be abundant evidence that traditional cultural patterns break down in cities, and also that the high numbers of contacts with individuals, not part of one"s circle of regular social acquaintances may lead to mental disturbance defined here merely as behavior generally considered "disturbed" by the majority of the society. It is important to note that antisocial behavior and "mental illness" are found in all cultures, and that indeed the same disorders recognized by Western psychiatrists are found even in primitive peoples. Therefore, we can be reasonably certain that lack of an evolutionarily "natural" environment is not the sole cause of such behavior. Nevertheless, that lack may well serve to aggravate the problems of people living in our most crowded, smoggy, and impersonal metropolises.
Stanford psychologist PG Zimbardo has concluded that urban pressures are transforming Americans into potential assassins. He based his conclusions on experimental studies of the connection between anonymity and aggression, and on field studies of vandalism. He noted an estimated 230 violent urban outbreaks in the period 1964-1969, and reported that in 1967 vandals in New York City alone wrecked 360,000 pay telephones, broke 202,719 school windows, and did damage to parks and transit systems costing some $850,000. Cars were abandoned on streets of a large city (New York) and a small one (Palo Alto, California), and secretly watched to see if there was a difference in vandalism between the two localities. The New York car was virtually demolished within three days by 23 separate attacks by looters and vandals, nearly all in view of passersby and during the daytime. The Palo Alto car was not molested for more than a week. How much (if any) of such behavior might be reduced if density were lowered is unknown, but at least the anecdotal evidence seems to indicate that high density is a factor in such problems. Crime rates are some five times as high in urban as in rural areas. Though some of this difference may be due to disparities in reporting, not all of it can be explained on this basis. Rates for violent crimes have been shown to be positively correlated with actual population densities in American cities. This general correlation held for statistics taken in three different years, 1940, 1950, and 1960, in the same cities. The rises in assault and robbery with higher density were particularly striking, although murder and rape both also reflected the trend. Robbery is the only one of the four that does not most commonly occur between acquaintances. Interestingly, crime rates in the suburbs have been rising in the past few years, especially among teenagers from relatively affluent areas, although their crimes are more often acts against property than crimes of violence. The writer holds that ______.