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.” Also: Linguist Geoff Nunberg considers the use of the word “they” as a gender-neutral pronoun. [Fresh Air] www.npr.org