She sits pretty on the railing of a bridge, smiling at the camera. A clear blue sky above her and a river far below. She is holding the end of her red saree about her head, as if bracing against the wind. If a picture says a thousand words, the 20-year-old’s photograph tells the sweet story of a newly wed woman. What it doesn’t say is, it is also her last photograph.

On August 16, when Rupali Patel toppled over the Mandleshwar bridge in Madhya Pradesh into a Narmada in spate, she and her husband were busy posing for selfies. A moment of distraction ended it all for her. That very day, some 300 km away at Mandsaur, a mother-daughter duo met with a ­watery end. They, too, were clicking selfies. They were the latest in a country that stands out as the world capital for selfie deaths.

It’s not just death by selfies. In the sweet spot of the world’s digital revolution, something strange is ­happening in India: a mysterious relationship ­between new technology and human ­behaviour. In August, dangerous stunts for video-sharing app...