Robert Winston returns for a new series, beginning by assessing the youngsters' ability to be happy. He discovers which areas of the brain develop self-confidence and contentment - and finds illuminating patterns when comparing the children's results with their parents'. Further tests identify the optimists and pessimists within the group, as well as revealing how resilient they are.

Professor Robert Winston examines how children's development is affected by the bonds with their siblings, a relationship thought to be even more important than that between parent and offspring. He asks why some brothers and sisters get on well and others loathe one another, and tests the youngsters' temperaments to learn how they respond to differential treatment.

Professor Robert Winston finds out how the six-year-olds are distinguishing between right and wrong, discovering the ways in which upbringing affects values in later life.

Professor Robert Winston presents an interactive show in which the children's ability to pick up new skills is tested through a series of elaborate games and puzzles. He also meets people who use all their senses to learn, including a former world memory champion and a man with synaesthesia.