In 2015 a woman in Saskatoon was strangled by a belt. Did her friend do it? She has been strangled by a belt that lies next to her body - the same belt her best friend was wearing in a photograph of the two of them that was posted on Facebook earlier that evening. What can really be learned by what we choose to post online? And what might cause a friendship to take a violent turn?On this episode of Bad People, Dr Julia Shaw and Sofie Hagen explore the psychology of “breaking up” with friends, the role of social media for teens’ mental health, and why people so rarely murder their friends.CREDITS Presenters: Dr Julia Shaw and Sofie Hagen Producer: Laura Northedge Assistant Producer: Hannah Ward Editor: Anna Lacey Music: Matt ChandlerCommissioning Executive: Dylan Haskins Commissioning Assistant Producer: Adam Eland#BadPeople_BBCClip: The He Lab “About Lulu and Nana: Twin Girls Born Healthy After Gene Surgery As Single-Cell Embryos” Audio clips: CBS News and Saskatoon StarPhoenix