Since late-night shows became a staple of network broadcasting in the 1950s, hosts have developed recurring ‘signature bits’ that inject their programs with a sense of offbeat silliness. The first generation of late-night hosts – like Steve Allen and Jack Paar – inaugurated this tradition, which has lightened up TV’s nighttime hours for more than seven decades. Beginning with Johnny Carson’s psychic “Carnac” character and extending to James Corden’s “Carpool Karaoke,” signature bits have become American pop culture touchstones. 
 
This video features exclusive interviews with Wayne Federman, Alan Zweibel, Jeff Foxworthy, Jason Segel, Judd Apatow, Margaret Cho, Conan O’Brien, Pete Holmes, and Craig Ferguson.