Sexual science constitutes the empirical study of sexual function and behavior in living beings. It originated from natural philosophy and is now characterized by the methods and aims of modern science. This chapter treats the main story of sexual science, starting with conceptual concerns over the body and using examples from Chinese and Islamic medicine. Next, the analysis shifts to the foundations of sexual science in the Western world, examining philosophical and medical traditions that culminated in medieval scholasticism and institutions like universities and hospitals. The chapter then treats the Scientific Revolution and the Enlightenment, in which contemporaries invented the “two-sex” model and pioneered new ideas of “biopolitics.” The analysis turns the nineteenth century’s complex “discovery” of sex and the powerful connections between global imperialism and sexual understanding. The chapter concludes with the dynamics surrounding the body and sexuality in the global twentieth century, as found in evolutionary biology, sexology, and psychoanalysis, and the relation between mass culture and ideals of the sexual revolution. Sexual science appears paradoxical: sometimes, it seemed an agent of discipline and power, supporting entrenched values, or it seemed to help emancipate individuals, debunking prejudices and superstitions and liberating attitudes and behaviors.

Relationship problems relating to sex and desire, including mismatches in desire and how to successfully address these; mismatches in preferred sexual activities and how to address these; the value of couples counselling for all couples.

Many vertebrate animals engage in masturbation and it is also prevalent in primates. Given the gregarious nature of this order, this is perhaps surprising, since, by definition, it occurs to the exclusion of others. Our research maps the masturbatory landscape of the primate order, highlighting the distribution and diverse forms self-stimulation of the genitalia takes: from an infant vervet monkey grasping his own penis in his mouth, to female chimpanzees using water spigots to stimulate their clitorises. We also examine the causation of this behavior. While autosexual behavior can be a substitute for allosexual interactions, many acts of masturbation seem to serve functions, which fall broadly under two categories: avoidance of pathogen transmission and reduction of mate competition. In terms of implications for human public health, the finding that masturbation is ubiquitous throughout the primate order, practiced by wild-living members of both sexes and all age-groups is a strong counter-argument to voices who condemn human masturbation as "unnatural."

Some sexual killers choose victims in a particular age group. Three killers described here (Igor Irtyshov, Clifford Olson and Arthur Bishop) preferentially targeted children and young adults. Olson was an all-round career criminal who showed bisexual tendencies. Vladimir Vinnichevsky killed very young children, while Anatoly Biryukov sexually attacked and killed babies. Vasily Kulik tortured cats, and later showed a preference for killing children. His switch from young adults to children and elderly women followed damage to his head, which could have harmed his brain. Bishop gave an account of craving, ambivalence, escalation and fighting temptation. He illustrated the difficulty of trying to resist intrusive thoughts (something that psychologists call the ‘white bears effect’). For Irtyshov, the form of rape and choice of victim reflects the assaults that were earlier inflicted upon him.

A relatively large number of serial lust killers were adopted as young children. It appears that those who commit sexual violence against women feel a resentment against their mothers for their adoption. In turn, this fuels resentment against either women in general or those having characteristics in common with their mothers. This would be in addition to the general factor of the disturbance of bonding, which might be common in cases of adoption. The chapter looks at three cases of killers who held such resentment. David Berkowitz was sexually excited by shooting at courting couples, but did not have any sexual contact with his victims. He masturbated to associated imagery. Jack Unterweger was a celebrity in Viennese cultural circuits but killed sex workers in association with having sex with them. Steve Wright killed sex workers in association with having sex with them.

Though the history of sexuality has diversified and enlarged our understanding of Victorian culture and practices, literary criticism, influenced by the courtship plots of canonical novels, has lagged behind. Even as we denounced a generation of historians and scholars for thinking Victorians were repressed, we canonized a literature based on heteronormative courtship narratives and traditional gender roles. We then critiqued that literature for adhering to – or championed it for subverting – those traditional narratives. In fact, Victorian fiction was always wilder and woollier than we gave it credit for being. Drawing on multiple novels, including examples by Wilkie Collins, William Ainsworth, and George Meredith, as well as the history of sexuality, including texts by Elizabeth Blackwell and Havelock Ellis, this essay surveys instances in which non-reproductive sexuality – pre- and extramarital flirtations, same-sex eroticism, desirous ephebes, and other kinds of non-genital or unconsummated sexual activities – are presented as typical behaviors within the novel. Just as conventional marital plots provide form for instances of what scholars have understood as managed desire, these texts suggest other formal possibilities and properties – rather than arcs of crisis and resolution, they may offer more episodic structures of sustained, oscillating, or unresolved tensions.

Puzzling over the repetitive evocation of sexologists such as Havelock Ellis during debates over the age of marriage in the Legislative Assembly, this chapter studies sexology as a site for the dissemination of the age-stratified sexual morality upheld by the Child Marriage Restraint Act. The marriage manuals, antimasturbation tracts, samples of erotica, and sex education texts surveyed in this chapter drew equally on the new science of sex and shastric knowledge and were particularly focused on the regulation of sexuality with reference to children. In making rough translations between two epistemic and ethical orders, these works buttressed an age-stratified sexual morality, gave chronological age roots in (a primordial) India, depicted marriage reform as a return to a (Hindu) golden age, and helped align the time of the (Hindu) ritual body with the temporality of secular body and of the modern nation. While such translations might have aided marital reform, the silent exclusions – of Muslims in particular – that were inherent to this schema could not be covered over for long.