What goes wrong in the brain to cause developmental disorders of the mind? Autism and dyslexia are examples of developmental disorders. These disorders are of genetic origin, but the only way to diagnose them currently is by behavioural criteria. The behavioural problems that are characteristic of these disorders have their root in remarkably high-level cognitive functions, that is, communication, social interaction and language. The challenge is to assess these problems, to explain their causes, and to explore ways of overcoming them. I am keen to explain the research I am involved in to the general reader and make people aware of the nature and development of complex mental functions. Over the next few years my plan is to write a book jointly with Chris Frith about the biological basis of social interaction and communication. More: Why study both autism and dyslexia? Dyslexia and autism are disorders with a genetic cause and a basis in the brain. To understand them, it is necessary to consider two very different types of factors, factors that are internal to the person and have a biological basis, and factors that are external, and have a basis in the social and cultural environment. External factors, for instance, educational programmes, can promote compensatory learning and useful coping strategies. We do not yet know what limits compensation in the developing brain, and why learning of one skill can be very difficult, while learning of another and just as complex skill can be easy. Such differences in the ease of learning have led me to believe that there are start-up kits in the brain/mind that enable fast track learning, and that, sometimes, these start-up kits are faulty or missing. Even more: Start-up kits in the mind? Throughout my career I have been investigating how problems in start-up kits might result in disorders of development, and what it tells us about the structure of the mind.