There is a reasonably popular idea that

the gap in knowledge acquisition widens

between those who read and those who don't.

This phenomenon is observed in other situations and is called

the Matthew effect.

It evokes that the rich will become richer and the poor poorer.

The term is from an American sociologist Robert King Merton (1968).

It refers to a sentence from the Gospel according to Matthew:

"For to those who have, to them will be given, and they will have abundance,

but from those who have not, even what they have will be taken away."

It isn't totally accurate because

reading is not always an obligatory condition.

But it is generally accepted that reading dramatically helps ...