Archives of Sexual Behavior, Vol. 22, No. 2, 1993 A Factor Analysis of the Klein Sexual Orientation Grid in Two Disparate Samples James D. Weinrich, Ph.D., 1,4 Peter J. Snyder, Ph.D., 2 Richard C. PUlard, M.D., 3 Igor Grant, M.D., 1 Denise L. Jacobson, M.P.H., 1 S. Rende Robinson, R.N., M.A., M.F.C.C., t and J. Allen McCutchan, M.D. 1 Many researchers interested in sexual orientation can be separated into two camps: The "lumpers," who try to reduce sexual classifications to as small a number of categories as possible, and the "splitters," who try to show differences among groups and individuals that make classification schemes increasingly difficult and~or intricate. We report factor analyses of the Klein Grid (a questionnaire with 21 sexual orientation items) to see how many factors emerge in two samples of strikingly different origins. In both samples, the first factor to emerge loaded substantially on all of the Klein Grid's 21 items. This factor accounted for a majority of the variance. In both samples, a second, correlated factor emerged which indexed a separation between most of the items and those having to do with social and~or emotional preferences. In both samples, a third correlated factor also emerged, but this factor differed between the two populations: one refined the social~emotional distinction and the other distinguished ideal behavior from past and current behavior. We conclude on the basis of our analysis that both the lumpers and the splitters are correct. KEY WORDS: Klein Grid; sexual orientation; factor analysis; limerence; lust. Supported by NIMH grants IP50 MH 45294 and R01 MH 43298. 1HIV Neurobehavioral Research Center, University of California, San Diego, 2760 Fifth Avenue #200, San Diego California 92103. 2Department of Psychiatry, Hillside Hospital---Research, Long Island Jewish Medical Center, P.O. Box 38, Glen Oaks, NY 11004. 3Boston University School of Medicine, Department of Psychiatry, 85 E. Newton Street M-905, Boston~ Massachusetts 02118. 4To whom correspondence should be addressed. 157 0004-0002/93/0400-0157507.00/0© 1993PlenumPublishingCorporation