The Romans invoked Fortuna, the goddess of luck, to explain the unexplainable; fortune-tellers study tea leaves to predict the unpredictable. In Blueprint: How DNA Makes Us Who We Are, Robert Plomin defies the ancients and the mystics, promising that your fortune can be predicted and explained by your genes.
Plomin is a psychologist who built his scientific reputation on twin and adoption studies of intelligence, academic achievement and mental health problems. In a book that urges working ‘with the grain’ of your unique gifts, Plomin’s talents as a scientist are clearest in the first half of the book, where he narrates the major projects of his tentacular career — first an adoption study in Colorado, then a US-wide study of adolescent siblings, and finally a twin study in the UK.
A reader new to the subject will learn a lot from these early chapters about the logic of twin studies and the ‘big findings’ of behavioural genetics. The biggest finding of all is that ‘everything is heritable’. If you had inherited different DNA, you would be different, and not just different in eye colour and height. You might be smarter and more outgoing; you might watch less TV and drink less alcohol; your wife might not have left you and your dog might not have bitten you.
In large part thanks to Plomin’s tireless scientific pace, this conclusion regarding the ubiquitous impact of nature is no longer all that scientifically controversial. And, as his first chapter describes, it is not really news. Most people already believe that our body weight and intelligence and personality have at least something to do with our genes. Nevertheless, many readers will feel a reactionary thrill while reading Blueprint. Plomin is violating an academic taboo by stating plainly that genetic differences should be taken seriously when we try to understand people’s lives.