The head of our nursery/K told parents to please not encourage or even use the term “best friend” or “bff” because she felt very strongly that preschool/early elementary kids with a best friend developed less robust friendship skills. She said even if it seems clear that your kid really preferred another kid, we should still encourage them to have a variety of play dates and not label the preferred friend as a best friend. It did seem to eliminate some of the best friend drama that I saw at our prior school, for example, kids telling each other “you can’t hang out with so and so because we are best friends”. It also helped break up the parent cliques, which was maybe the main motive of the head of school! Hmm…