One hundred cases of self-injury, comprising 39 self-cutters and 61 self-poisoners, were interviewed when they became able to describe the act: 83 in a casualty department, 17 in a hospital. Standardized recordings were made of their feeling state before and after the act, together with an account of the social circumstances under which it occurred. The information was obtained in a way which allowed comparison with existing animal data on self-injury, although comparisons were made between what is known of animal behavior in this area and human feelings as reported by these subjects.
The results indicate similarities between what is known of animal self-injury and self-cutting in man in the form of the injury, in the social situation preceding the act, and in the agitation preceding it. Similarities also exist, but are less close, for the self-poisoners. The most obvious effect of the act is a reduction in tension; this may constitute its physiological value.