'New Yorker' staff writer Jia Tolentino writes about how social media shapes identity, public discourse and political engagement, particularly for millennials like herself. She talks about growing up in a Houston megachurch, her devastating year in the Peace Corps, and how religion led her to MDMA. Her new book of essays is 'Trick Mirror.' Linguist Geoff Nunberg considers the use of the word "they" as a gender-neutral pronoun, and jazz critic Kevin Whitehead reviews the new album, 'The Balance,' from South African composer Abdullah Ibrahim.