Developmental eras in older adulthood is defined most often, as older adults - the elderly persons, golden-agers, senior citizens or "the old" are treated as if they were a single developmental cohort. However, recently, some writers have begun to make distinctions in older adulthood between the "young old (those from 65 to 74 years of age), the "old old" (those 75 - 84 years of age), and the "oldest old" or "very old" (those 85 years of age and older), even though these are properly chronological rather than developmental distinctions