Robin Dunbar (2013) The Science of Love and Betrayal Faber & Faber, London; 320 pp.; ISBN 978-0-57125345-6 [originally published 2012]
Robin Dunbar is Professor of Evolutionary Psychology at Oxford and in this clearly written and entertaining book he looks, from a biological perspective, at why we fall in and out of love and how an intimate relationship looks and feels to those involved. Along the way he explores some academic controversies about the purpose and origins of pair bonding but these are never so intrusive as to overwhelm the story. While there are some descriptions of brain function and the roles of various chemicals, the narrative is lucid and tailored to the general reader.
Dunbar explores love as it is expressed between couples, mother and child, friends and relatives. Each of these kinds of love is somewhat different (and triggers different areas of our brains) but they share many of the same psychological and physical benefits. We are happier and healthier when we love someone.
Human brains are complex and despite decades of research we still know very little about how they work. The role of some key proteins and hormones is clearly important, but exactly why these are triggered and how the brain processes them remains a mystery. We are highly sensitive to physical contact with others and to visual cues from other people, the latter skill taking decades to fully develop. While other mammals fare better than us at using smell and taste to process information, we still retain a capacity to assess other people using these senses. Deep kissing is not just about checking whether those teeth are false.
The evolutionary link between brain size, language, social group size and pair bonding is complex and an area where there are competing theories. Dunbar has a preferred position but it does not stop him from presenting the other options and the thinking behind them.
What do we find attractive in others? We take into account our feelings and our personal advantage, as well as the character and physical appearance of the other person. Dunbar teases out some of the key elements, though some of the research is based on contestable methods. Essentially we prefer hourglass shaped women and tubular shaped men, the more symmetrical the better. No tubular belles, then.
Dunbar asserts that we can really only love one other person at a time, but this assumes that the love of each intimate partner always takes the same form. Observations of polygamous marriages and other ménages would suggest otherwise. There is a limit to the number of those we can love or befriend, despite what online social media would have us believe. Dunbar estimates that about 150 people is our maximum load and that includes friends and lovers now deceased. Our intimate circle, including any current partner, hovers around five people at best. Relationships require a lot of maintenance and effort, and if they are to become close this involves a lot of face to face interaction. We just do not have the time and resources to spread the love too far.
Of course, friendships and relationships fail. Over time our intimate circle can change and this is increasingly true as people participate in a globalised economy and where long distance travel and migration are more common. Yet the reasons for breaking up are relatively few and include things we can manage with a bit of effort. Jealousy though can rear its ugly head, and in the most intimate relationships can lead to violence and death.
In two of the later chapters, Dunbar looks at the history of religious love – how individuals fall in love with a spiritual being. This is an unusual kind of love because it is all created in the mind of the believer. This means the ‘partner’ can be perceived as perfect and so any failings become the fault of the believer. Dunbar then links this to modern online relationships. For many people, those we interact with most online are also the ones we see face to face on a regular basis anyway (which rather begs the point of going online in the first place). But we can meet and develop relationships with people online that we have never met in person, and an online identity can easily be falsified. In such cases we are creating in our imaginations the person that we think we love. It is the ideal set-up for predators and scammers, but when we are besotted critical thinking takes a long and lonely hike.
While there is much of interest in this book, and many titbits that will spice up conversations and debates, there are some shortcomings. Like a lot of psychological research in particular, heavy reliance is put on correlations to show that there is a meaningful link between two things. But correlations do not prove causation, even if they are ‘statistically significant’: not breathing is fully correlated with death, but it would be facile to argue that ceasing to breathe is the reason why people die. In many cases cited in this book more convincing evidence would have strengthened the case and Dunbar needed to be more open about the weaknesses in much of the data.
The book covers a range of relationships but very early in the piece Dunbar says that the processes he describes apply to heterosexual couples and that he assumes they will also apply to homosexual couples and all variations in between. This is a very large assumption and he presents no evidence for it. The reason is that his evolutionary psychology approach carries a supposition that the purpose of pair bonding is to reproduce the species and that relationships are structured with this end in mind (if not always consciously). Unfortunately, this is not true for many species, let alone humans. A great deal of love and physical intimacy is not directed at reproduction at all. As Dunbar notes early on, love and intimacy give us substantial psychological and physical benefits – as well as simply being enjoyable. Reproduction is one factor but by no means the only one or always the most important – we seek loving partners for a range of reasons. The book needed a much broader vision.
Long-term monogamous relationships might be an anomaly in human evolution. Dunbar notes that modern hunter-gatherers tend to practise serial monogamy and this was probably true for early humans. Dunbar’s logic would suggest that the rise of settled agriculture and villages provided the conditions for long-term monogamy but he fails to explore this. In turn, modern industrial society has the potential to further change relationships. Dunbar gives little space to polyandry and indeed there are few societies where it is an accepted cultural norm. But in looking at alternatives to male-female pairs he examines mother-maternal grandmother pairs as a good child rearing option and notes these are common in poor African American households where males are mobile and often absent. A similar pattern has been observed in poor urban Aboriginal households in Australia. This is polyandry in practice: households centred around a female and male partners moving in and out of them. It seems the conditions of high male unemployment, low male education levels, policies that push mobility of labour, and welfare provision for single mothers can combine to make polyandry an attractive option. It will be interesting to see if the current economic crisis in southern Europe changes household composition in this way.
In looking at why pair bonds evolved, Dunbar favours the explanation that they did so to protect a woman and her children from the predations of other men. Dunbar in fact wavers between protection of the woman and protection of the children and his argument is not wholly convincing. The rise of religion, the fact that all major religions support the dominance of men over women, and the linkage to settled agriculture is a theme that needed to be considered in Dunbar’s analysis but sadly it is entirely absent.
Finally, I think Dunbar could have said more about online relationships in the modern era. He points out some of the dangers, including impairing our ability to learn visual cues, but other benefits from face to face intimacy are also lost. We cannot touch, smell or taste someone online and visual cues are only two-dimensional, so much of the toolkit that we use to assess and understand other people is taken away from us. We are walking into an online jungle with one hand (and often both) tied behind our backs. What will this do to us as a species and our ability to fall in love?
There is much food for thought in this book. The ideas are clearly laid out and there is a rich bibliography. Dunbar is obviously very bright, but I found this book intellectually unadventurous – pleasant but safe. I yearned for a bit more excitement and a broader perspective. It’s love after all – let’s live a bit!