There are things we accept as obvious truths that aren't necessarily backed up by data. A primary example: cousin marriage being taboo. In this episode, data journalist Mona Chalabi looks at the numbers behind our family trees to reveal that cousin marriage is much more common and much less "ick" than you might think. Want to hear more from Mona? Check out her podcast Am I Normal? with Mona Chalabi, from the TED Audio Collective. Want to hear more from Mona? Follow Am I Normal? on Apple Podcasts: https://link.chtbl.com/AINyta Visit http://TED.com/ to get our entire library of TED Talks, transcripts, translations, personalized talk recommendations and more. The TED Talks channel features the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design -- plus science, business, global issues, the arts and more. You're welcome to link to or embed these videos, forward them to others and share these ideas with people you know. Become a TED Member: http://ted.com/membership Follow TED on Twitter: http://twitter.com/TEDTalks Like TED on Facebook: http://facebook.com/TED Subscribe to our channel: null TED's videos may be used for non-commercial purposes under a Creative Commons License, Attribution–Non Commercial–No Derivatives (or the CC BY – NC – ND 4.0 International) and in accordance with our TED Talks Usage Policy (https://www.ted.com/about/our-organization/our-policies-terms/ted-talks-usage-policy). For more information on using TED for commercial purposes (e.g. employee learning, in a film or online course), please submit a Media Request at https://media-requests.ted.com/