According to Foucault, how might capitalism generally control bodies, including their reproduction?
In Discipline and Punish, Foucault discusses how the penal system has had the illusion of progress. It does seem that humanism influenced a more humane use for prison systems. He describes a trajectory from torture to regimented and monitored incarceration. Indeed, imprisonment is more humane than calculated torture. But Foucault argues that it is a strategic move (not necessarily a humanistic one) corresponding to increased use of similarly regimented and monitored infrastructures in other aspects of life.
These notions of discipline and control, which Foucault frames in terms of the modern prison system, are used in all aspects of life to create for the individual only a sense of true/free individuality. In other words, those in power brainwash "individuals" by giving them certain places to do certain things. You learn in schools. Art is to be in museums. People work in factories. The military is an ordered regiment. This all seems obvious and not harmful. But Foucault is making a wider argument about power structures and how these categories and predetermined spaces and places are part of the exercise and abuse of power. He explains how this whole infrastructure of discipline literally and figuratively controls bodies. Hence, he uses the phrase "docile bodies" to describe how subjects and citizens are submissive, perhaps without even knowing it.
To pull this off, those in power must be able to constantly observe and record the bodies they control. Companies do just that, now more than ever. They observe what people are buying, selling, smoking, drinking, reading, watching, and they record and use this information. Through analysis of this information and using careful manipulation (via advertising, media, and other forms of information), capitalists can persuade and encourage them to buy certain products. Think of online companies like Amazon and Pandora giving you "feedback" with statements like "If you liked this, you will like . . ." If such companies and governments are able to control what these bodies (people) eat, drink, sleep in, watch, read, and so on, they control nearly all aspects of their lives. Falling under that all inclusive umbrella of life and culture, entertainment and politics, are notions of relationships, gender, sexuality, and reproduction. Foucault's philosophical project is all about examining how power is used to control all of these aspects.