Although the term "aging" might conjure up only a few wrinkles in one's mental imagery, there is much more to aging than the physical aspects. There are four different types of aging discussed in the text: chronological, biological, psychological, and social aging. There is a necessary distinction between these categories of aging. They are unique in the description (i.e. 70 years of age, wrinkled skin, Alzheimer's disease, a senior citizen, etc.), but related because these descriptions determine the "age" of an individual.
Chronological age describes the years that have passed since the individual was born. A 60 year old, was born 60 years ago and is therefore chronologically older than a 30 year old who was born 30 years ago. There are certain expectations that come from being a certain chronological age such as your physical appearance. Although there are exceptions, one could easily guess an individual's age (within 10 years) just by their physical appearance.
Biological age describes the physical "wellness" of the individual. As a person ages, certain physical changes occur. Organs deteriorate and certain organ cells cease to replicate. The conditions of most organs are consistent with the chronological age of the individual, with the exception of individuals who overuse certain organs (i.e. an alcoholic's liver).
Psychological aging refers to the deterioration of an individual's sensory and perceptual processes, mental functioning, adaptive capacity, and personality (Hooyman and Kiyak, 2002). This covers a very wide range of functions such as speech and even intellect. Certain mental disorders are consistent with a certain age group. One would find it typical for an elderly person (70 or older) to experience Alzheimer's disease, but would find it atypical for a 20 year old to experience Alzheimer's disease.
Social aging refers to an individual's changing roles and relationships with the family and the rest of society (Hooyman and Kiyak, 2002).