And yes I am a parent, and was somewhat lazy as my kids were not out of diapers until right at the age of 3 but all of our friends still didn't even try until their kids were 4. Heck I can remember being 4 years old and running around my grandparents farm and popping a squat right out in the open field and burying it just like the barn cats around there. I almost find it child abuse to allow your kid to be so unconscious about their bodies that they have no problem crapping on themselves when in other cultures 4 year olds are cutting up fruit with machetes (personally seen in a small village, Africa).
[0]: https://en.wikipedia.org/wiki/Toilet_training#History_in_the... [1] http://dshs.texas.gov/wichd/