When Charles Darwin sat down to calculate whether he should marry, his logical mind concluded it was a catastrophic waste of time and money. However, his eventual decision to wed reveals a powerful truth about how we choose meaning over efficiency. Discover why the most rational man in history ignored his own data to find a companion better than a dog.

Why do we feel an emotion as potentially catastrophic as love, and what do our fingers have to reveal about our fidelity? Evolutionary psychologist Robin Dunbar breaks down the startling biological reality that humans are essentially 'serial monogamists' by nature, driven by a neurochemical cocktail designed to ensure offspring survival. He reveals the 'show-off hypothesis' behind male risk-taking and explains why the common kiss is actually a sophisticated biological audit of your partner's immune system.