A pair of twin girls is born in the late 1980s and their mother, Chris, is told a series of ‘facts’ about them.Each born with their own placenta, Chris is told it’s extremely unlikely that her twins are identical, but, if they were, they’d be a perfect DNA match. She’s also told that her daughters have a much higher likelihood as adults of conceiving twins themselves.These were the foundations of how Chris and her daughters understood their ‘twin-ness’ as they grew. But in recent years, new research has proven that none of these assertions is true.So what has science learned about twins in recent years and what are the mysteries that researchers are still trying to solve? And even if you’re not a twin, maybe you were at some point in your development? There could be a way to find out very soon.For RN Summer we're playing some our favourite programs from the past year. This program was first broadcast in February 2022.GuestsProfessor Jeff Craig@DrChromoProfessor in Epigenetics and Cell Biology at Deakin University School of MedicineDeputy Director, Twins Research AustraliaChris KulasElizabeth Kulas’s motherJennifer KulasElizabeth Kulas’s twin sisterHostElizabeth KulasScript editing by Joel Werner