Final answer:
The increase in the number of interest groups can be attributed to new interests in society, the rise of institutions and corporate interests, and changing societal attitudes.
Step-by-step explanation:
The massive increase in the number of interest groups can be traced to several factors. One reason is the development of new interests in society. As societal attitudes change and new issues emerge, people become more aware of them and start forming groups to address these issues. For example, the advancement of science and technology has led to the rise of interest groups advocating for or against stem cell research.
Another factor is the increase in the number of institutions, corporate interests, and public interest groups. Telecommunication companies and medical research firms are examples of the types of groups that have seen growth. Additionally, the opportunity to become more civically engaged and the increased specialization of industries have contributed to the formation of interest groups.
In summary, the growth in the number of interest groups is a result of new interests in society, the rise of institutions and corporate interests, and changing societal attitudes. This expansion allows people with common concerns to organize and advocate for their interests.