Empirical research documents the risk that alienation allegations will prevail over child abuse allegations in custody cases despite evidence to the contrary (Silberg & Dallam, 2019 Silberg, J., & Dallam, S. (2019). Abusers gaining custody in family courts: A case series of overturned decisions. Journal of Child Custody, 16(2), 140–169. https://doi.org/10.1080/15379418.2019.1613204[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]; Milchman, 2017a Milchman, M. S. (2017a). Misogyny in NYS custody decisions with parental alienation versus child sexual abuse allegations. Journal of Child Custody, 14(4), 234–259. https://doi.org/10.1080/15379418.2017.1416723[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). This article analyzes oversimplified beliefs, implicit or explicit, about alienation that support such practice. Professionals demonstrate oversimplified beliefs that lend unjustified credibility to alienation claims when they assert or imply that they observed alienation directly rather than inferring it from behavioral observations; that their inferences are unambiguous in their meaning; and that the validity of their inferences is not compromised by difficult-to-detect risks to the child (Milchman et al., 2020 Milchman, M. S., Geffner, R., & Meier, J. S. (2020). Rhetoric replaces evidence and reasoning in parental alienation literature and advocacy: A critique. Family Court Review, 58(2), 340–361.[Crossref], [Web of Science ®] , [Google Scholar]). They support these oversimplified beliefs when they claim that suggestibility research calls the validity of abuse interpretations of the behaviors they observed into question. The adversarial nature of the legal system in the U.S. and other countries encourages acceptance of oversimplified beliefs about alienation because blaming one parent for the child’s rejection of the other is consistent with legal concepts of personal responsibility and with legal remedies that directly control the behavior of the person deemed responsible (Meier, 2022 Meier, J. (2022). Questioning the scientific validity of parental alienation labels in abuse cases. In J. Mercer and M. Drew (Eds.), Challenging parental alienation: New directions for professionals and parents. Routledge. [Google Scholar]). A forthcoming companion article discusses empirical findings related to alienation claims that these oversimplified beliefs support.