When a man with outstanding hair is able to take home a female beyond his looks and/or stature. Essentially the woman is drawn to the hair and hair alone, but is required to bring the man home as well because of his physical attachment to it. All members of Hanson are fervent lobbyists for the exogenous hair effect. Additionally Robert Pattison's teeth remain unrecognized because of this.
Zach Galifinakis attempting the "Phil Effect" in the Hangover. Also known as the "John Cusack Effect". "How has Jason Schwartzman ever gotten laid? ....The Exogenous Hair Effect."