“…All traits were previously found to be largely independent of one another (Nichol, 1990). ASUDAS procedures are based on well-established criteria for scoring intratrait variation, and proved reliable in many preceding studies (e.g., Scott, 1973Scott, , 1980Turner, 1985aTurner, , 1987Turner, , 1992Sakuma and Ogata, 1987;Sakuma et al, 1991;Haeussler et al, 1988;Turner and Markowitz, 1990;Irish and Turner, 1990;Irish, 1993Irish, , 1994Irish, , 1997Irish, , 1998aIrish, -d, 2000Jackes et al, 2001). Traits are recorded using 23 rank-scale reference plaques that help standardize scoring by providing representations of minimum, maximum, and common intermediate expressions (Turner et al, 1991).…”