THE GREAT SPANISH neuroanatomist Santiago Ramón y Cajal believed that with personal commitment and willpower we can do almost anything with our brains. “Consider the possibility that any man could, if he so wished, be the sculptor of his own brain, and that even the least gifted may, like the poorest land that has been well cultivated and fertilised, produce an abundant harvest.”

The long-standing academic argument over the relative importance of nature and nurture in the development of intelligence has led to a narrow focus on certain aspects of brain function to the exclusion of the really important ones ‑ those that give us self-esteem, self-belief and satisfaction in our lives. There is no doubt that our genes (nature) and our environment (nurture) both contribute to brain development. Cajal was more interested in the additional role that each of us has in determining our own brain development.