Human sexuality has the subject of study for thousands of years. To gain an understanding of the research methodologies employed in serious scientific studies, however, a reasonable starting point would be the groundbreaking work of the research team of William Masters and Virginia Johnson. As their research was conducted during the modern era – the late 1950s to the 1990s – there is much information surviving that illuminates the methods they employed in their attempts at developing a scientific basis for human sexuality. Their two main studies, Human Sexual Response and Human Sexual Inadequacy, provided valuable insights into the topic of their research. While Alfred Kinsey’s work on sexuality, which he conducted during the late 1940s and early 1950s, paved the way for the subsequent work of Masters and Johnson, Kinsey was entirely dependent upon surveys or questionnaires designed to elicit honest answers regarding human behavior. It was, consequently, of limited scientific value.
The methods used by Masters and Johnson went well beyond those of their predecessor, Alfred Kinsey. In addition to detailed surveys of men and women to develop a framework for how to approach their research topic, the team, who eventually married and later divorced, used hundreds of human subjects, split roughly equally between genders, with a slight preponderance of the female side of the equation, to study responses to external stimuli. Through the use of human subjects, the research team was able to witness firsthand the physical transformations that occurred with both genders during exposure to certain stimuli.
The pioneering methods employed by Masters and Johnson established a scientific precedence to future research into human sexuality. A major advancement, however, was unavailable to them during the height of their academic activities. Modern imaging, particularly through magnetic resonance imaging (MRI) equipment, has enabled researchers to gain a detailed image of the human brain, as well as of other parts of the body, during periods of sexual arousal. This technological advance has extended knowledge of human sexuality in a way Kinsey never imagined, let alone the ancient Hindus were assembling what became the Kama Sutra thousands of years ago.