1. The mere act of investigating social behaviour may alter the very behaviour that is being observed:
When people come to know that they are being closely watched and observed they may not behave in their usual way. The presence, personality and actions of the observer can disrupt the behaviour that is being investigated.
2. People — unlike flies or worms, mountains or aero planes — have emotions, motives, and other highly individual personality characteristics:
They may give false information deliberately or unintentionally or by ignorance.
They may fail to understand a question put to them or they may misinterpret it. They may cancel certain facts for reasons of their own. They may also behave in unpredictable ways for a variety of peculiar reasons of their own. It is for this reason sociological explanations and predictions are often less precise than those of the physical sciences.
3. The origins of social behaviour are almost always extremely complex, involving many social, psychological, historical and other factors:
Establishing the cause-and-effect relationship is highly problematic here. It is relatively easy to establish why water boils and how fire bums and bomb explodes. It is much more difficult to establish why people fall in love, why do they kill, why do they lie, etc. The causes of social behaviour are usually innumerable and intricate.
4. For ethical reasons it becomes difficult to perform certain kinds of experiments on human beings:
These moral questions do not disturb the physical scientists who are experimenting with water, gas, rays, minerals, etc. In the human world, the dignity and privacy of human beings must be respected. We cannot deliberately make the young boys to stay with young girls separately for a couple of days or weeks just to test or assess the intensity of sex-morals, which have already been taught to them.
Similarly, we cannot make husbands to divorce their wives to study the impact of divorce on children. Ethical considerations place severe limitations on the methods the sociologists can use.
5. The sociologists, unlike the physical scientist, are part of the very subject he or she is studying. It is therefore very difficult for a sociologist to maintain objectivity or detached attitude towards his own study. An astronomer may look at and observe the heavenly bodies without being disturbed emotionally.
On the contrary, the sociologist who is studying issues such as communal riots, race relations, ethnic conflicts, etc. can become passionately involved in the outcome of the research. The researcher may identify strongly with the problems and experiences of the subjects. As a result, the process of investigation and interpretation get distorted.
Sociologists are aware of these problems involved in their research work. In spite of these problems they aim to make sociology as exact and precise a science as possible. Most of the sociologists probably accept the viewpoint expressed by Max Weber many decades ago. “Weber believed that sociology must model itself as far as possible on the natural sciences, but its subject-matter, being so different, sometimes also calls for an interpretative, subjective approach.”
As Ian Robertson has pointed out “subjective interpretation — which Weber called ‘Verstehen’, or sympathetic understanding — is in no sense a substitute for the scientific method. Wherever possible, the conclusions drawn from subjective interpretation must be verified by the scientific method.”