In 2013, a team of neuroscientists from the University College London published a paper on how neurodevelopmental disorders can affect a child's educational outcome. They found that up to 10% of the human population suffer from specific learning disabilities, or about two to three children in a (Western) classroom. Such conditions include dyscalculia, dyslexia, attention deficit hyperactivity disorder (ADHD), and autism spectrum disorder. They are caused by abnormal brain development due to complicated environmental and genetic factors. A child may suffer from multiple learning disorders at the same time. For example, among children with ADHD, 33-45% also suffer from dyslexia and 11% from dyscalculia. Normal or high levels of intelligence offer no protection. Each child has a unique cognitive and genetic profile and would benefit from a flexible education system.