It reviews the concept of criminal responsibility, particularly as applied to children, and looks at findings from psychological research into cognitive, moral, and conative development. Cognitive development refers to mental processes such as learning, using and understanding language, memory, thinking, and perceiving. Insufficient development of these faculties may compromise an individual's ability to be aware of the wrongfulness of an illegal act (mens rea) and thus, release the individual from personal fault. In cognitive development, persons at age 7 are considered able to make judgments about the intent of others. Moral development, thought to underlie lawful behavior, has been closely linked to cognitive development. However, much controversy surrounds the attachment of moral developmental stages to criminal responsibility. The Young Offenders Act removes the issue of moral development from the issue of criminal responsibility. Conative development refers to the growth of free will, self-control, and the ability to resist impulses. For persons to be considered criminally culpable, they must have conscious and voluntary control over their behavior (actus reus). This review of developmental competencies concludes that most children at age 7 meet at least the minimum criteria for criminal responsibility. The Young Offenders Act has set the age of responsibility at 12. The Young Offenders Act defines an age zone (12 to 17 inclusive) where reduced responsibility is assumed. However, this paper suggests that it is more accurate to describe children older than 7 (or 12) not as having reduced legal responsibility, but as having decreased consequences for their acts, because of their social status. A total of 33 footnotes are provided.