Shakespeare speaks of the seven ages of man, but from the medical point of view man has been considered in three periods: childhood, when we practice pediatrics on him; the grown-up stage, when we have no special term for our procedures; and old age, when we now say that he is a candidate for geriatrics. [...] norxshop.com

Through his research, Dr. Jerome Kagan, a psychologist at Harvard University, found two types of children: One, by the middle of the second year, is timid and shy, fearful and wary. The other is outgoing, sociable, and not easily frightened. Both types can come from similar families. By school age, half the fearful children Dr. [...]