Chapter 9: Assessing Civil Capacities

The assessment of civil capacities represents a specialized domain within forensic psychology that addresses the tension between preserving individual autonomy and ensuring protection for vulnerable populations. Modern approaches reject the historical global competency model, where a single determination of incompetence stripped individuals of all decision-making authority, instead recognizing that functional abilities vary across different contexts and domains. This shift reflects decades of evolution in forensic practice, prompted in part by Grisso's influential critique of early evaluation methods, which suffered from conceptual confusion about legal standards, reliance on clinically irrelevant data, and inappropriate intrusion into judicial determinations. Contemporary evaluations employ standardized frameworks that decompose competency into measurable functional, causal, interactive, and dispositional components, complemented by structured assessment instruments validated through empirical research. Evaluators must navigate substantial practical challenges, including temporal fluctuations in an individual's capacities and implicit biases that may lead to unfounded assumptions about capacity based on unpopular decisions rather than genuine functional deficits. The chapter examines four major civil capacity domains. Guardianship proceedings determine whether the state should appoint a surrogate decision-maker, with modern jurisdictions offering both plenary and limited guardianship arrangements to calibrate the degree of autonomy restriction. Financial capacity evaluations employ specialized instruments like the Financial Capacity Instrument to assess both concrete skills and abstract judgment regarding money management, requiring clear and convincing evidence due to the substantial liberty interest at stake. Testamentary capacity focuses on the individual's understanding of the will's purpose, natural heirs, and asset extent at the time of execution, often evaluated retrospectively through psychological autopsy methods when challenges emerge after death, with particular attention to undue influence. Capacity to consent to treatment and research derives from informed consent doctrine, requiring communication ability, informational understanding, rational deliberation, and appreciation of consequences, supported by instruments such as the MacArthur Competence Assessment Tool and the Capacity to Consent to Treatment Instrument. Growing demand for these specialized evaluations reflects demographic shifts toward an aging population requiring ongoing assessment and intervention to sustain decision-making capacities.