Geez, I really think it depends on the child. I have had 5 one year olds start, directly into full-time no issues at all. As well, have 1 that started over a month ago...transitioned in gradually. This is his first full week (Mom goes back to work next week). Definitely see baby tips in improvement but he's still screaming most of the day. I honestly don't think any increased amount of transition would have helped him (especially with Mom here).