In the 19th century, the Viennese physiologist Franz Joseph Gall placed a formidable thumb on the scales of the ‘nature vs nurture’ debate when he proposed a simple – and, as we now know, false – solution to the age-old conundrum. Everything you need to know about someone’s character, he argued, could be predicted by the shape of different brain regions – and by extension, the contours of their head. That phrenology, as it became known, was built on conjecture rather than empiricism was clear to a great many scientists of the era. Still, it caught on in the public consciousness, and often with sinister consequences. This animation from BBC Reel provides a brief history of phrenology, shedding light on why facile solutions often gain traction over rigorous empiricism, and how pseudoscience can sometimes open gateways for the real thing.