Gerontophobia is the name given to the fear of ageing and the elderly.
Discrimination and ageism have been strongly linked to gerontophobia.
This unreasonable fear or hatred of the elderly is associated with the fact that someday all young people will grow old and that old age is associated with death. This unwillingness to accept death manifests in feelings of hostility and discriminatory acts towards the elderly.
On a lighter note ! This amusing video from You Tube contains some amusing sterotypical observations.