Humans are a bit like onions. Not in the “are a bit smelly and make you cry” sense but in the sense that to understand us you have to take the time to peel back the layers of cause until you reach our core. As an evolutionary anthropologist that core is always evolution itself. At the basis of all our behaviour, or indeed traits, is the basic drive to survive, reproduce and ensure the survival of our children so our genes carry on down the generations. This is what drives all life on earth. But on top of this there are many other layers relating to our brains, our genes, our environment and our culture.
Take how you experience romantic love as an example. At the most basic level love is a neurochemical reaction in your brain which induces a sense of warmth and euphoria which motivates you to make contact with the object of our desire and work to maintain a relationship with them (with the obvious end point that you will have kids and your genes will happily go off and persist down the generations). This is driven by the big 3 “love hormones” oxytocin, dopamine and beta-endorphin. We all have access to these hormones. But to what extent these hormones have an influence on us is down, in part, to our genes. So how much dopamine I generate when I hug my husband and how many receptors I have in my brain to be affected by it is individual to me.
On top of this the mechanisms underpinning this neurochemical phenomenon are also impacted by my upbringing; the environment. Children who are raised by sensitive and engaged carers tend to build structures and mechanisms in their brain which allow them to have healthy and functional relationships as adults. Children who are not lucky enough to experience such parenting do not and may be left with deficient or ineffective neurochemical mechanisms which mean they struggle to form healthy relationships when older. So my genes and my environment cause me to have a very individual love experience as do yours.
But the layers do not end there. Because just under the surface of our onion is culture, that arguably uniquely human trait. For how we view love – describe it, celebrate it, condone or condemn it – is strongly influenced by the culture in which we were brought up and live. In the West we believe strongly in the existence of romantic love, driven by centuries of poetry and story telling where true love overcomes all. But in other cultures the concept of romantic love does not exist or is only condoned after marriage. In many cultures love is bound up in religion or elaborate ritual and is as much about the bringing together of two families as it is of two individuals. While in others marriage can be very private; two people on a remote beach.
So our onion is complex; evolution + genes + brains + environment + culture. But our outer layer is where the curve ball sits. Because there is no overall formula for understanding the experience of love. We know it has the elements I have described but at the end of the day there is always an element of the unknown. Humans are wonderfully complex and clever and there is an element of all our behaviour which is just down to some unknown, and hopefully always unknowable, aspect of the individual. And that is what makes my job fascinating. For at the end of the day there is always an element of behaviour that is unique to the person in front of us, and that is what makes us wonderful.