An act against femicide Picture: ARMAND HOUGH, ANA

In the midst of the outrage about gender-based violence (GBV) in South Africa, many women have come out about how their bodies reacted when they were raped. 

Experts say female bodies can have involuntary physiological responses even to unwanted sex-related stimulation.

In a Ted Talk, sex educator Emily Nagoski breaks down one of the most dangerous myths about sex and explains the science behind arousal nonconcordance.

She says there's a disconnect between physical response and the experience of pleasure and desire.

Research over the last 30 years has found that genital blood flow can increase in response to sex-related stimuli even if those sex-related stimuli are not also associated with the subjective experience of wanting and liking. 

In fact, the predictive relationship between genital response and subjective experience is between 10 and 50 percent. 

WATCH: The truth about unwanted arousal

Nagoski says: "Nonconcordance (unwanted arousal) is when there is a lack of predictive relationship between your physiological response, like salivation, and your subjective experience of pleasure and desire. 

"Which is an enormous range. You just can't predict necessarily how a person feels about that sex-related stimulus just by looking at their genital blood flow."

"In the age of Me Too and Time's Up, people ask me 'How do I even know what my partner wants and likes'? Is all consent to be verbal and contractual now? There are times when consent is ambiguous and we need a large-scale cultural conversation about that. But can we make sure we're noticing how clear consent is if we eliminate this myth?" asks Nagoski.

Nagoski also touches on gaslighting: "You say you feel one way but your body proves something else." And then she hits the nail on the head by describing how US judges presiding over sexual assault and rape cases made mention of how female victims recorded a physical response, but "this is not a sexual response".