Aging of characters in The Simpsons
Wikisimpsons - The Simpsons Wiki
The aging of characters in The Simpsons has been a subject of common fan debate, the passage of time is clear, but characters show small, if any, signs of aging, despite openly saying that years have passed. The writers and character designs seem to ignore the issue of aging.
Common theories
Eternal youth
One common theory is that, like in many cartoons, the characters never age and are trapped at the age of their first appearance.
Slowed time
Another common theory is that, because only one half-hour episode airs approximately each week, the flow of time in The Simpsons is considerably slower than in real life. This theory is supported by the apparent, though minimal, growth of the characters, as well as the noted marks of time.