Final answer:
Quantitative sociology is the use of aggregate data to study individual behavior through questionnaires and surveys.
Step-by-step explanation:
The use of aggregate data to study the behavior of individuals is called quantitative sociology. This involves collecting data from subjects who respond to a series of questions about behaviors and opinions, often in the form of a questionnaire. The collected data is then represented numerically and analyzed using statistical methods such as surveys with large numbers of participants.