Answer:
This indirect measures are necessary for society due to the fact that they help to shape social relations among its individuals.
Explanation:
Social psychology is the science encouraged of studying the ways in which human beings interact and share knowledge among themselves. These mentioned indirect measures are implicitly there located in consciousness, they just occur while people do not realize that they are using some prejudices located in mind according to social awareness, that is why this kind of behavior is called by the author automatic prejudice.