Johansson was born in New York City on November 22, 1984. Her father, Karsten Johansson, is a Danish-born architect, and her paternal grandfather, Ejner Johansson, was a screenwriter and director. Her mother, Melanie Sloan, a producer, comes from an Ashkenazi Jewish family from the Bronx. Johansson has an older sister, Vanessa, who is an actress; an older brother, Adrian; a twin brother, Hunter (who appeared with her in the film Manny & Lo); and an older half-brother, Christian, from her father's first marriage.
