Recently I read that schools will sometimes separate school friends into different classes with one parent on an online forum saying in 2013 that:
The principal admitted that they try to separate friends each year.
This issue was even brought up on Parenting Stack Exchange in 2015 and then in 2019 on Moms.com. The Moms.com article covers some of the effects this policy might have on the child. The general idea being that it should help reduce distractions in class and improve independence. It could also encourage the development of social skills by forcing the child to make new friends.
Aside from anecdotal reports from parents is there any academic research into the effects of such a policy that proves it doesn't just cause the child distress and loneliness?