What is the MacDonald triad (MacDonald triad)?

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Last updated: May 17, 2025View editorial policy

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From the Research

The Macdonald Triad is a set of three behavioral characteristics, including animal cruelty, fire-setting, and persistent bedwetting, that were proposed as potential warning signs for predicting violent behavior, but modern research has largely discredited it as a reliable predictor of violent behavior. The three traits were suggested by psychiatrist J.M. Macdonald as potential indicators of a higher risk for developing into violent offenders later in life, with the theory proposing that these behaviors stemmed from childhood trauma, neglect, or abuse, creating a psychological foundation for later violence 1. However, studies have shown that while some violent offenders may have exhibited these traits, many people who display one or more of these behaviors never become violent, and many violent criminals never exhibited the triad 2, 3.

Key Findings

  • The Macdonald Triad is not a reliable predictor of violent behavior, and its use as a diagnostic tool is limited 1.
  • The presence of one or more of the triad behaviors may be indicative of dysfunctional home environments or poor coping skills in children, rather than a specific predictor of violent behavior 1.
  • Current psychological and criminological approaches focus on multiple risk factors rather than this specific set of behaviors when assessing potential for violence.
  • Research has shown that enuresis, one of the traits in the Macdonald Triad, is associated with attention-deficit/hyperactivity disorder (ADHD) and other comorbidities, highlighting the need for a comprehensive assessment of children exhibiting these behaviors 4, 5.

Implications for Practice

  • Clinicians should be cautious when using the Macdonald Triad as a diagnostic tool, and instead consider a comprehensive assessment of multiple risk factors when evaluating potential for violence.
  • Children exhibiting one or more of the triad behaviors should be assessed for underlying trauma, neglect, or abuse, and provided with appropriate support and interventions to address these issues.
  • Further research is needed to fully establish the validity of the Macdonald Triad and its individual constituents, and to explore the relationship between these behaviors and other problematic outcomes 1.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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