https://www-psychologytoday-com.cdn.ampproject.org/c/s/www.psychologytoday.com/us/blog/freedom-learn/201911/kindergarten-teachers-speak-out-children-s-happiness?amp

The research is clear. Academic training in kindergarten has no long-term benefit. In fact, it may cause long-term harm. It does not reduce the education gap between the rich and the poor, which is the usual reason offered for such training.