It's also tied to an increased high-school graduation rate. There is no one best method of teaching reading. What works for one child may not work for another. Phonics, a reading strategy that starts by children learning letter sounds, then words containing those sounds, and finally the words in stories, is fine for him. Whole language works the opposite way from phonics.
First children learn to read by listening to stories while looking at words.
Then they practice words from the stories, and finally they learn to sound words out. There is nothing wrong with either child, or with either method. In fact, it's the method, not the reader, that is the problem. To boost your child's motivation and enjoyment of reading, learn to recognize your child's individual reading style. If we focus on kids' strengths, not their weaknesses, they learn to read faster and better.