Here’s a great article summarizing some newly published research about children learning to read at various ages: Research Finds No Advantage In Learning To Read from Age Five. It’s worth reading. I thought these were a couple of the best quotes:
“One theory for the finding that an earlier beginning does not lead to a later advantage is that the most important early factors for later reading achievement, for most children, are language and learning experiences that are gained without formal reading instruction,” says Dr Suggate.
“Because later starters at reading are still learning through play, language, and interactions with adults, their long-term learning is not disadvantaged. Instead, these activities prepare the soil well for later development of reading.”