If a loved one seems to change his personality overnight, don't be surprised.
Take heed of the psychologists from Long Island University in New York who wrote a report on personality changes for the International Journal of Aging and Human Development.
Their study followed a group of people, all around 65 years old, for eight years to see how their attitudes and feelings changed over time. Most people mellowed and became less angry as the years passed.
When the researchers examined what caused these personality changes, they cited marriage, divorce and death of loved ones.
Surprisingly, changes in career, where they lived and personal associations outside of the immediate family had no effect on personality.