Pain is defined by the individual experiencing it. There are no biochemical markers that establish the degree of pain, and so reliance is placed upon the individual to convey the type and severity of her or his pain, whether verbally or by behaviors such as moaning, avoiding activities, or taking steps to seek relief. Scaling showing that subjects can reliably discriminate between pain descriptors (Melzack & Torgerson, 1971) has led to attempts to distinguish between different pain conditions on the basis of the language used to describe the sensations, and these endeavors have resulted in a pain adjective checklist known as the McGill Pain Questionnaire (Melzack, 1975). Early studies suggested that different pain conditions could be distinguished by the profiles of adjectives checked (e.g., Dubuisson & Melzack, 1976). Subsequent studies suggest there may be less specificity than originally thought, with individuals varying on the dimensions of intensity and the relevance of affect-laden words (Reading, Hand, & Sledmere, 1983), but less reliably on sensory descriptors.