There are less than four sororities in Brown University .
There are 11 residential Greek houses : six fraternities ( Beta Rho Pi , Delta Phi , Delta Tau , Phi Kappa Psi , Sigma Chi , and Theta Delta Chi ; four sororities ( Alpha Chi Omega , Kappa Alpha Theta , Delta Gamma , and Kappa Delta ) , one co-ed house ( Zeta Delta Xi ) , and one co-ed literary society ( Alpha Delta Phi ) .