DS started at 3 - 2 mornings a week. He would not have enjoyed it before then as he could not understand why the other children could not/did not talk and play like he did. He was always very careful and did not like the seemingly random acts of violence/impulsivity of the other toddlers. We did play groups etc but it was to be honest more for my benefit than his. At 3 he coped much better with other children(who were mostly 4-5) and his social confidence with kids really grew (always fine with adults). For a child with a different personality it might be completely different but I will always be happy he stayed home as long as he did.
