The first player is the one with the largest head circumference. A handy tape measure is provided to determining this.
Players move their pieces (brains) around the board attempting to be the first one to the finish. Players take turns turning over cards, and all players must vote on which card describes them best. The group by majority moves forward, by the number of votes in this majority group.
The mechanics are such that it is in the interest of all the players, including the player who is being analyzed to vote how they think that person is perceived. Perhaps the player may become a bit stereotyped, but it can be very revealing.
There is little point for strangers to play this game and the game can be unbalanced everyone does not know each other at least to the some extent.