The study of an individual's choice about what type of computer to buy is a subject of

The answer is microeconomics. This is the sociology that reviews the ramifications of individual human activity, particularly about how those choices influence the use and dispersion of rare assets. Microeconomics demonstrates how and why diverse merchandise have distinctive qualities, how people make more effective or more gainful choices, and how people best arrange and participate with each other.

answer; researchers typically cannot control people's sexual behaviors as would be necessary in an experiment;

are there any options?