When children learn the alphabet, they often can recite "A, B, C, D and W, X, Y, z" before they can recite the letters in between. Why is this?
This can be explained by the serial-position effect.
The serial-position effect is the tendency of a person to recall the first and last items in a series the best, and the middle items worse.
This is divided into two sub-effects.
The Primacy Effect is the tendency of an individual to remember a primary set of variables in a series or stimulus. The items in the beginning are usually mentioned primarily.
The Recency Effect is the tendency of an individual to remember recent or the last variables in a set of series or stimulus. The last items are usually mentioned later.