The following post is based on an article by the American Federation of Teachers, "Waiting Rarely Works: Late Bloomers Usually Just Wilt." This post will define and compare the developmental lag theory and the early reading weakness as a skill deficit.
The developmental lag theory states that some children learn to read more slowly than others, and that these children will eventually catch up with their peers. This theory says that reading problems will diminish as the brain develops. The “early reading weakness as a skill deficit” theory believes that children who are behind in reading do not catch up without intense intervention. These students need direct instruction as soon as possible so that they do not fall farther behind. The developmental lag theory does not take into account children who have learning disabilities or children who just might need more individualized reading instruction because it assumes that all children will improve their reading skills naturally as they grow. The other theory accounts for these students and emphasizes the importance of working with them as soon as a delay is noticed. It acknowledges that students need instruction in order to learn to read, and some need more assistance than others.