Arousal may be spontaneous, or arise in response to sensory stimulation, memory, fantasy or emotional connection. Here’s how to understand the differences

What turns you on? Depending on the person, the answer to that question will vary wildly. But what is really going on under the, ahem, hood when we start to get in the mood?

The first scientists to really take the physiology of sex seriously – or at least break the taboos around talking about it – were William Masters and Virginia Johnson, sexologists who began their studies in the 1950s (and got married in 1971). “They came up with what’s known as the four-stage model, which was that the body gets aroused, you hit a plateau, you have an orgasm, you go back down to baseline,” says Dr Angela Wright, a GP and clinical sexologist based in Yorkshire.