Friends do it, strangers do it and so do chimpanzees - and it's not just deeply embedded in our history and culture, it may even be written in our DNA. The humble handshake, it turns out, has a rich and surprising history. In this week's episode palaeoanthropologist Ella Al-Shamahi speaks to science broadcaster Helen Czerski about a funny and fascinating voyage of discovery - from the handshake's origins (at least seven million years ago) all the way to its sudden disappearance in March 2020. We’d love to hear your feedback and what you think we should talk about next, who we should have on and what our future debates should be.  Send us an email or voice note with your thoughts to podcasts@intelligencesquared.com or Tweet us @intelligence2.  And if you’d like to support our mission to foster honest debate and compelling conversations, as well as ad-free podcasts, exclusive bonus content, early access and much more, become a supporter of Intelligence Squared today. Just visit intelligencesquared.com/membership to find out more.  Learn more about your ad choices. Visit podcastchoices.com/adchoices