It has long been a goal of many religions and philosophical approaches for humans to rise above our animal nature. We have obviously gone a long way since our time as hunters and gatherers, and our discovery of science and creation of technology has been remarkable. When it comes to our sexual desires and mating habits, we have certainly created many sophisticated social rules, but it is less clear that we can really get much beyond what our evolutionary history has created for us.  If there is such a thing as human nature, then evolutionary psychology has a strong claim to be able to tell us what it is.

Helen Fisher’s 1994 book Anatomy of Love aimed to tell us what our nature.  She set out a good deal of evolutionary theory and evidence to tell us about the circumstances that led to our deepest instincts and needs, and she argued that this shed considerable light on the roles of love and sex in our current society. Since then she has published THE FIRST SEX: The Natural Talents of Women and How They are Changing the World (1999), WHY WE LOVE: The Nature and Chemistry of Romantic Love (2004), and Why Him? Why Her?: How to Find and Keep Lasting Love (2010). Now she has updated her 1994 book for a second edition of Anatomy of Love. She explains that she has added more information about the biology of personality, love addiction, adultery, divorce, and sexual selection and mate choice, as well as results from a collaboration with match.com. Some of these ideas are also in her TED talks, which are linked to on her web page. There is also a whole new separate website devoted to the book, at which you can take quizzes and watch more videos.  It seems to be run by Fisher and Lucy Brown, a neuroscientist at Einstein College of Medicine.

There is no doubt that the book has plenty of interesting ideas and useful information. It presents a sophisticated view, which recognizes that whatever biology supplies is molded by different societies and cultural norms, and that trends change over time as other societal conditions change. Nevertheless, it is silent on a lot of moral and even scientific issues, which make it a less useful book. One of the central issues the book does discuss is the length and nature of relationships between men and women. Fisher points out that humans do form committed relationships where they devote themselves to one person. She also points out that primates tend not to form lifelong relationships, but stay together for as long as it takes to have offspring and nurture them them to maturity. Furthermore, it is very rare for primates to be completely sexually exclusive with one partner. Yet Fisher says nothing about whether humans should be more accepting of people having relationships outside of marriage, whether sexual exclusivity is a realistic goal, or whether the idea of committing to one person in marriage for the rest of one’s life.  She says very little about her own personal life, and there’s not even any information about her personal life on the book jacket, on her website, or Wikipedia. Of course, there’s information out there: a 2009 newspaper article, for example, says that had a partner for 30 years until his death. Nevertheless, it is a easy to conclude from Fisher’s work that humans are fighting their own nature when they pledge themselves to sexual exclusivity and lifelong commitment. Maybe to argue this explicitly would make the book more shocking, but it is surprising the book does not address the issue more fully.

It is even more surprising that this revised edition says so little about homosexual relationships. She does not even say why she avoids this topic.  It isn’t just that there isn’t a chapter on gay sex: there’s hardly a paragraph about it in the main text.  There is a long footnote, speculating on the causes of homosexuality. It is completely accepting of gay sex, and there’s no hint of the old views in sociobiology that argued that since homosexual sex didn’t lead to procreation, it was unnatural. Nevertheless, it is strange that what is obviously a large topic is so neglected here.

It’s also odd that Fisher glosses over the difference between sex and gender. There are many ways to make this distinction more precise, but the basic idea is that sexual difference is about biology, while gender difference is about culture and psychology affected by society. Fisher is very definite that there are major overall differences between men and women, but the index has no listing for “sex differences” and a longish list of sub-topics for “gender differences,” including aggression, intelligence, intimacy, jealousy, math, motor skills, and verbal skills.  Her view is clearly that these differences come from our evolutionary history and thus are basically biological, and hence it is jarring to see them listed as to do with gender. But it reflects the exclusive focus on evolutionary biology, so that other approaches get neglected or subsumed.

The largely unwritten assumption of Anatomy of Love is that evolutionary biology is the key to our understanding of love and sexual behavior, and other approaches just fill in some of the minor details. However, that’s implausible. The biology provides some explanation for some phenomena that don’t take much observation to notice: people tend to cheat, long relationships are difficult to sustain, and there are differences between men and women.  Many readers will decide that Fisher’s approach is reductive and weakened by her neglect of more sociological and anthropological explanations. More fundamentally, there’s the “so what?” question. Just knowing that there’s an explanation of trends in sex and love doesn’t help much in deciding how we should live. Humans have the ability to decide how to live, so, for example, knowing that primates tend not to have sexually exclusive relationships does not tell us much about how we should behave. Justifying extra-marital affairs by saying that they are natural is a fallacy, the naturalistic fallacy, to be precise. That’s not to say that evolutionary biology could not be the basis of a sexual morality, but for that to be possible, it needs to be supplemented by clear and reasonable guidelines for how much people in a modern society should aim to live in accordance with their evolutionary past.

© 2016 Christian Perring

Christian Perring, Professor of Philosophy, Dowling College, New York