http://www.cam.ac.uk/research/discussion/school-starting-age-the-evidence
We clearly at PeKI, raise the same flag of pay attention and respecting the time for playing and not teaching anything that compromises the precious moments of a balanced childhood.
The article suggested is from the University of Cambridge is: " School Starting age: the evidence"
"This is a brief review of the relevant research evidence which overwhelmingly supports a later start to formal education. This evidence relates to the contribution of playful experiences to children’s development as learners, and the consequences of starting formal learning at the age of four to five years of age"
See more at: http://www.cam.ac.uk/research/discussion/school-starting-age-the-evidence#sthash.IgdRjSh0.dpuf