All identified pupils will work with pupils of the same chronological age so that they are part of a normal peer group. (inspirationtrust.org)
I actually think this is pretty common for a younger child (I'm talking birth order, not chronological age). (askmoxie.org)
Other mature dogs (by chronological age) can continue to stay fit and lean long past the age at which you begin to think they might slow down. (dogfoodinsider.com)