Do girls toilet-train earlier than boys?

What studies found

In a study that followed about 270 American children through toilet training, half of girls were staying dry during the day by about 32½ months, and half of boys by about 35 months. Girls reached nearly all the toilet-training steps a little earlier, and girls and boys went through the steps in much the same order.

Within each group, children varied a lot. For each step, the ages of the middle half of girls were spread over about 7 to 11 months, and of boys over about 7½ to 14½ months.

A large Danish study of children born around 1960 also found girls were dry and used the toilet a little earlier, on average. A small study that checked 59 children closely from birth found no real difference between girls and boys.

What we don’t know yet

Why girls tend to be a little earlier, and how much this depends on when and how families start toilet training.

The studies

• Schum et al. 2002
• Flensborg-Madsen et al. 2019
• Jansson et al. 2005