To prepare for her role, Nicole Kidman visited women's shelters and talked to former victims of abuse for inspiration.
The racist white man on the train who berates the porter is played by Allison Davis, a Chicago attorney who is black.
The mole on the side of Anthony Hopkins' head was added, due to the fact that Wentworth Miller has a mole on the side of his head.
In a 2003 op/ed piece in The New York Times, writer Brent Staples reported that Philip Roth's inspiration for the Coleman Silk character was the New York Times literary critic Anatole Broyard, who "passed" for white for the last 40 years of his life, and perpetuated his deception so completely that even his two children did not know their father was black until just before his death.