Guided by specific theoretical and methodological points of view--the phylogenetic perspective and the universalistic approach respectively--this paper reports on a worldwide study of the antecedents and effects of parental acceptance and rejection. Parental acceptance-rejection theory postulates that rejected children throughout our species share in common a constellation of personality characteristics different from the personality dispositions of accepted children. Specifically, rejected children are more likely than accepted children to be hostile, aggressive or passive aggressive (or to have problems with the management of hostility and aggression), to be dependent, emotionally unresponsive, emotionally unstable, to have impaired feelings of self esteem and self adequacy, and to have a negative world view. In addition, the theory postulates certain worldwide antecedents of parental rejection and acceptance, and the theory also predicts certain expressive systems outcomes to parental acceptance-rejection. Cross-cultural and intracultural tests confirm hypotheses derived from acceptance-rejection theory. (Author)