Links have been made between an increase in mental health issues in children and the early introduction of formal approaches to learning in schools. The psychologists reported that children become more aware of their physical and mental ability through different kinds of physical and social play and that this play allowed them to become increasingly 'self-regulating', both intellectually and emotionally. 'Children need time for unstructured play, which gives them opportunities to learn about their world, explore ideas and soothe themselves. The maturation of executive functioning is crucial to the development of an individual's control over any risk taking and impulsive behaviour: much of this control develops as a consequence of experience. All exercise promotes the production of the new brain cells and connections that are essential for rational thought and self-control. Different types of exercise support different aspects of cognition.