A main source for the ages
Sequential Acquisition of Toilet-Training Skills: A Descriptive Study of Gender and Age Differences in Normal Children
Timothy R. Schum, Thomas M. Kolb, Timothy L. McAuliffe, Mark D. Simms, Richard L. Underhill, Marla Lewis · 2002 · PEDIATRICS
- Children
- About 270 children
- Where
- Milwaukee, United States
- Ages
- 15 months to about 4 years
- How
- Parents filled in a survey every week
- What it found
- About half the girls were staying dry during the day by about 32½ months and about half the boys by about 35 months. Showing interest in the potty came earlier, at about 2 years.
- Limits
- We have only read the summary. Most families were white and from one city.