The researchers speculated that rapid social and biological changes, both common during adolescence and old age, might contribute to this common loss in self-esteem. The study was conducted through the Internet and gathered more than 325,000 responses. The participants ranged from 9 years to 90 years of age.
The results broke down as follows:
Respondents aged 9 to 12: Levels were the highest, and levels were similar among boys and girls.
Respondents in adolescence: Levels were much lower, and the drop in self-esteem was twice as great for girls than for boys. This gender difference in self-esteem remained throughout adulthood.
Respondents in post-adolescent years, college, and post-college: Self-esteem levels increased after adolescence and peaked in the mid-60s.
Respondents in their 70s and 80s: Self-esteems levels plunged for this age group, yet respondents in this age group narrowed the gender gap; those in their 70s had similar self-esteem while women in their 80s had slightly higher self-esteem than men.
The researchers suppose that the self-esteem decline in old age could be attributed to:
Loss of spouse
Decreased social support or socioeconomic status
Declining physical and mental health
They also postulated that the decline in adolescent years could have a lot to do with puberty.
Psychology and Aging September 2002;17:423-434
http://www.ncbi.nlm.nih.gov/pubmed/12243384?dopt=Abstract