It may seem difficult to fathom, especially given the degree to which so much present day pop culture resembles a fishing lure designed to catch their capricious attention, but there was a time when teenagers didn’t exist. Sure, there were actual people who were 14, 15 and 16 years old, but they weren’t a demographic entity, to be either pursued or pilloried. Director Matt Wolf’s fascinating new documentary Teenage, then, casts an eye backwards, to that time and the ensuing decades. The result — an engaging collagist work assembled from rare archival material, filmed portraits and voiceover lifted from early 20th century diary entries — is an impressionistic rumination on the birth and, well, development (let’s not say maturation) of youth culture. For the full, original review, from Paste, click here. (Oscilloscope, unrated, 77 minutes)