What inspires humans as sexual beings to respond to stimuli? This is the question that this article sought to address by reviewing a study by Masters and Johnson. The article’s main focus is a research conducted by the pair that observed the sexual responses of 694 participants with the goal of understanding the physiological aspect of sexual motivation (p. 160). The author also gives an account of how the researchers improved the sampling method used by shifting from the initial use of prostitutes for the study to obtaining a more credible and “representative sample” of the larger population (p. 161). The article also notes the procedures and measurements used as well as the observation techniques that were applied. An analysis of the results is followed by an evaluation of critical responses towards the research and recent studies that draw from the findings of this simple study.