I read the other day that 48% of people over the age of 85 suffer from senile dementia, and that this number increases steeply as people age. Sufferers have difficulty remembering events and people. Even in its early stages, it impacts on decision making and one's ability to form short and long term plans.
My question is, one of the reasons for having a voting age is because we believe that children and young people are cognitively unable to understand the full implications of voting. While this isn't true for all children, it is for the majority of kids, justifying an arbitrary, blanket voting age. If there is a point at which a majority of elderly people are cognitively unable to understand the implications of their vote, does this mean we should create an upper voting age limit?