The Role of Instinct in Criminal Responsibility and the Determination of Punishment under Iranian Criminal Law

Abstract

The present study examines the position of instinct in criminal responsibility and the determination of punishment under Iranian criminal law, with particular emphasis on the relationship between instinctive impulses, free will, culpability, and individualized sentencing. Although instinct is not expressly recognized as an independent ground for excluding criminal responsibility in the Islamic Penal Code, it may indirectly influence legal assessment through established doctrines such as coercion, necessity, legitimate defence, mental incapacity, mitigating circumstances, and judicial evaluation of the offender’s psychological condition. The study adopts a descriptive-analytical legal method and examines instinct as a factor situated between ordinary motivation and legally significant impairment of volition. Particular attention is paid to the instincts of self-preservation, defence, sexual desire, anger, and aggression, as well as their relevance to offences against persons, property, sexual morality, and religious or moral dignity. The analysis shows that Iranian criminal law does not treat instinct uniformly. In some contexts, instinctive pressure may contribute to the exclusion or reduction of responsibility when it substantially affects discernment or freedom of choice, whereas in other contexts it merely explains motive without altering liability. In cases involving sexual violence, uncontrolled instinct cannot constitute a legitimate mitigating factor and may instead indicate greater dangerousness. The study further emphasizes the importance of distinguishing motive, diminished self-control, and complete absence of responsibility, as well as the role of psychiatric and psychological expertise in assessing the actual effect of instinctive pressure on the offender’s cognitive and volitional capacities. It is concluded that Iranian criminal law has implicitly recognized the relevance of instinct, but in a fragmented and case-specific manner. A more coherent framework based on individualized culpability, proportionality, and objective criteria for impaired self-control would improve consistency in both criminal responsibility and sentencing.