Denmark; note that there is an <i>explicit</i> identifications of conditions in Denmark that may contribute, and may not be found elsewhere (notably, in the U.S.) regarding universally available alternative for those who do not enroll in kindergarten at 5.<p>This seems <i>mostly</i> to provide a step toward better understanding of developmental-stage appropriate pedagogy methods, especially given that Denmark has universal pre-K so that the children <i>not</i> going to kindergarten are <i>not</i> starting school later, they are transition between <i>styles</i> of education at a different point.