Preface

Why write another book about orgasm and human sex? Well, as Georgiardis et al. put it in two papers, "Sex is a fundamental pleasure and crucial for the survival of our species" and "There is nothing legal that comes close to orgasm pleasure-wise" [1, 2]. With possible exceptions, most human sex is not for procreation but recreation and pleasure [3, 4], although other factors may also play a role [5]. On the other hand, over-emphasis on pleasure may detract from the obviously important role of sex in procreation [6]. Every biologist should therefore have a strong interest in human sex, they wouldn't be reading this were it not for their parents having had sex, and hopefully enjoying it.

The first thing I want to emphasise is that I am not a medical doctor, nor a sex counselor, or a psychotherapist. Therefore, do not take anything here as medical or psychological advice. If you have any medical or psychological concerns, please go and seek expert advice. What I am, however, is a biological scientist, more precisely, mainly an entomologist, systematist, and evolutionary biologist, with a desire to make a lot of the complex medical and scientific literature available to a large audience of reasonably educated lay people.

Some few years ago, a friend of mine, knowing that I was a professor of biology and obviously interested in the subject, asked if I could write an online article about female orgasms for one of his websites. I did some (quite a lot of) research and wrote what I hoped was a passably accurate account. But this left me with many, many questions because I could not readily find definitive answers in the academic literature. Indeed, the more I read, the more contradictions I found. Loving to solve scientific problems, this led me to do more and more research, find more and more problems, delve even deeper, etc., and this book is the result.

One of the greatest difficulties that I have faced in this endeavour is that medical practitioners who publish papers on some aspect of female anatomy, sexuality or physiology, almost invariably do not present their data in the same way that most other biologists would. Medical scientific literature has a culture of presenting results that preclude others from doing further analyses. The great majority of the papers cited in this book present summary statistics, but hardly ever scatterplots and even rarer individual-based subject correlations. However, I have endeavoured to obtain raw data so that a more biological analysis approach can be taken.

Another difficulty in writing about 'normal' female sexual anatomy, histology, function, etc., is that the vast majority of the literature published in scientific journals does not concern the 'normal', sexually healthy woman, but instead focuses on women with various sexual dysfunctions or diseases. This is, of course, understandable because funding for research/publication is mostly tied to medicine, and of course, there is a great need for doctors to share potentially important information, case studies, etc. However, apart from MRI brain scanning (which, contrarily, has been almost totally focused on normal subjects), the great majority of normal sex response or anatomical studies are now rather dated, and most could well do with re-exploration using modern methods.

In recent years, there has been a marked increase in the scientific literature on female sexual function, and a far greater understanding of both mechanisms and variation is emerging. Techniques available for research had advanced in sensitivity and capability far beyond what was possible in the 1950s and 60s when female sex research really took off as a valid area of scientific and sociological study. Nevertheless, there remain controversies, and some indeed heated debates: notable examples being whether women can experience more than one type of orgasm or whether the G-spot exists. Regarding the former, thousands of women make up to researchers that they can differentiate more than one type of orgasm, which seems to have failed to impress some researchers who base their conclusions on physiological data. Similarly, with the G-spot, which many women say they are well aware of, the scarcity of evidence for a distinct anatomical (though there may be some) structure leads some to deny its existence. In both cases, the actual site of the woman's sensation could easily be in the brain itself based on perhaps subtle differences in the neural information it receives or interprets. Whether the orgasm originates from a specific structure or in the brain, it makes no difference when it comes to a woman's experience.

Since the early research of Alfred Kinsey et al. in the early 1950s and about a decade later by William Masters and Virginia Johnson, many thousands of volunteering women have participated in the laboratory investigation of their sexual arousal and orgasm, nearly all achieved by genital stimulation, yet studies in the scientific literature on anal or nipple-induced orgasms are essentially non-existent. Similarly, despite thousands of histological anatomical studies based both on biopsy samples and dissections of cadavers, there are precious few papers that describe normal histology either in detail or systematically across the sexual structures. Similarly, immunohistochemical research papers tend to focus on single systems with no study including all genital organs. Much is still to be learned about basic anatomy, and there are numerous contradictory statements in the literature that I attempt to resolve.

Whilst there are many books aimed at helping women achieve sexual satisfaction, there are few that really explain much of what is known about arousal and orgasm from a scientific perspective while still being accessible.

This book also includes a considerable amount of information obtained through anonymous elective surveys of women, and reveals several previously unrecognised or unreported trends. These results try to fill some of the gaps in the medical literature with primary, individual-based data.

It is also important to note that it is written largely with reference to studies in Europe, North America, Australia and some Spanish or Portuguese-speaking South American countries. Whilst human anatomy and physiology are largely similar, no matter where one comes from, societal norms can be very different. Some cultures openly practice masturbation [7], whereas this is not the done thing in the 'west' only.