Today on The Gist, criminologist and homicide researcher Adam Lankford explains why some mass shooters seem so drawn to extreme ideologies. Then we speak with 11-year-old author Audrey Hinsdale about how her debut novel The Trigger is a metaphor for growing up. For the Spiel, Mike weighs the cultural impact of driverless cars.Get The Gist by email as soon as it’s available: slate.com/GistEmailSubscribe to the podcast in iTunes: itunes.apple.com/us/podcast/slate…id873667927?mt=2Learn more about your ad choices. Visit megaphone.fm/adchoices