In recent decades, developments in neuroscience have given unprecedented insights into the way our brains work. But the discovery of neuroplasticity – the brain’s ability to change over time – has led to what Dr Hannah Critchlow calls “neurohype”: the suggestion we can change our fate by moulding our brains to our liking well beyond childhood. She leads us on a nuanced investigation into how much free will is actually left over once genetics, epigenetics, and physiological and societal factors are accounted for.
Without denying the existence of neuroplasticity, Critchlow argues that the way our brains are shaped during our lives may be largely predetermined, or at least beyond our control.
Nature (as opposed to nurture) plays an important role. This comes in the form of species-wide characteristics as well as genetic material specific to us, either because it has been passed down from our parents or mutated on the way. An example of a species-wide characteristic is our tendency to make cognitive shortcuts in processing information, which leads to energy-efficient but imperfect decisions based on recurring patterns that distort incoming information.
Our specific genetic material lands us with all manner of idiosyncrasies and even medical conditions, some of which can change our destinies in significant ways.
However, there are few instances where a single gene predicts the onset of a specific condition or can predict a life event. Usually, many genes are involved in any particular condition, and they are only one of many factors.
This makes it difficult to predict conditions, but where it is possible, it may give us autonomy at least to prepare for the onset of medical conditions or consider the risk of passing them on to the next generation. Even in the few instances where a single gene is responsible for a condition, such as Huntington's, there may be no way of curing it and, in the latter example, knowing your fate throws up many dilemmas without any clear answers. So there is a limit to the benefit of this extra autonomy.
Nurture – how our beliefs filter our beliefs
Although scientists are making rapid advances in modifying genes and diagnosing conditions in unborn children, they are quite limited in taking control of them. Much of Critchlow's argument is within the “nurture” category. As mentioned above, she confronts claims that neuroplasticity make us much more nurturable, not only by parents but by ourselves in later life. Although, in theory, our brains are very malleable – humans are born with much of the wiring in their brains still to be completed – the way this wiring process takes place is nevertheless determined by the environment a child grows up in and the behaviour of those surrounding them. Parents, in subtle ways, pass down behaviours and beliefs to their offspring.
The insight that I think will stay with me having read the book is the role our beliefs play in determining how we perceive reality – in other words, new beliefs are filtered by existing beliefs. Our core beliefs are to a greater or lesser extent determined for us (by parents, religious communities, school, social setting) so we may not be as free in our thinking as we like to believe. Taking into account how keen our brains are to take cognitive shortcuts to save energy, and the amount of effort it takes to rewire those belief systems, we all tend to make questionable decisions based on the beliefs that have been passed down to us, sometimes through several generations.
There are probably limits to just how freely we can think – but at least being honest about this gives us the chance to broaden our horizons, know our limitations and seek external support.
We do have some wriggle room, probably. One of the rather mind-bending implications: believing you are able to control your own destiny seems to lead to better outcomes. So positive thinking, Critchlow says, may be beneficial despite what she says at the beginning of the book. We may be able to change our behaviour a little by altering our environment: if you have trouble resisting sweet treats, don't let them into the house. This is nudge economics on a micro scale.
You can, with a lot of effort, possibly work actively on changing your beliefs, for example by practising gratitude and empathy. For me, this turns a lot of post-Enlightenment thinking on its head: rather than the pursuit of truth, the role of beliefs in changing how our lives play out could mean we should be pursuing a set of beliefs that enable a better set of outcomes. For example, even if our destinies are, in some objectively verifiable way, written before we were born, it is more important to believe otherwise if this makes us healthier and happier.
There's so much to learn from this book. It is compellingly written and full of fascinating nuggets, such as experiments on mice suggesting trauma can be passed down through generations epigenetically – rather than changing the genes, the way they are expressed is affected by previous generations’ experiences.
The issues dealt with in The Science Of Fate are food for thought not only for people wanting to optimise their personal lives, but also for those seeking a deep understanding of how intelligence, including artificial intelligence, works.