The Science of Love and Betrayal, By Robin Dunbar

Beauty is in the mind of the beholder

In the first throes of love, it is easy to forget that one's perfect partner is often an illusion. As the anthropologist and evolutionary psychologist Robin Dunbar suggests in his instructive study: "No one individual will be perfect on every single dimension." It is a salutary warning for those who have decided to hold out for Mr or Ms Right. Dunbar drives his point home: "We do not operate in an ideal world, we operate in a market." In choosing a mate, we are constantly in competition and unconsciously make compromises. As we age, our choices diminish and we are forced to settle for second, third or even fourth best.

As well as looking at the science of attraction – what happens in our brains when we fall in love – Dunbar offers an engaging analysis of the differences between the sexes in their choice of life partners. He argues that younger, fertile women are often the ones in the driving seat, suggesting that their choice of partner comes down to "cues of gene quality" such as facial symmetry and masculinity. At the same time, women want someone who will help to care and provide for their offspring. These desires, however, are often in conflict.

Dunbar gives reasons for the rise in internet dating, which, despite the success stories, can end in heartache or worse. The euphoria of meeting someone online feels safe, as with the unquestioned acceptance of religious love: "You can invent the perfect partner. Your dreams can never be contradicted by the intrusion of brute reality. The Beloved is tailor-made for you ... There is no blemish of character or form, because you can construct the Beloved to mirror precisely the traits you long to have in the perfect partner." In religious love, you are unlikely to be betrayed. In virtual reality, you can be seduced and scammed by strangers adopting a persona.

Dunbar covers familiar ground, such as our inclination towards partners who resemble our parents, and how passion tends to wane three years into a relationship, but he always offers a refreshing take. One interesting observation is that on beginning a new relationship, we often drop two of our most intimate friends – the intensity of feeling divides our time and attention.

The Science of Love and Betrayal is an empowering read. Only by better understanding why we act in certain ways or what is prompting a particular emotion can we make the necessary choices to improve our love lives.