• The disease model of mental illness may have outlived its usefulness. • A new theory suggests that some mental disorders are evolved cognitive styles that benefit the group. • The neurodiversity movement has long advanced a similar vision.

• Psychologists have long debated whether ADHD is a deficit or a distinct cognitive style. • A recent review of the evidence suggests that ADHD traits might have helped early humans. • This evidence should prompt us to consider how we can change our educational systems to benefit, rather than hinder, this cognitive style.