Author’s practical guidance
"Why is his different from mine?"
Source named in the book: children's questions about bodies (Friedrich)
This is a question about categories, not about anatomy.
Say this now
“Boys have a penis. Girls have a vulva. That's the difference.”
The whole answer at four. Then stop.
“Good noticing. What else did you notice?”
Treats it as observation, which is what it is.
Do this
- Answer in one sentence and wait. The follow-up question tells you what they actually wanted.
- Same words every time. Answers stay dull.
- Say "most" rather than "all" if you want an answer that will not need undoing later.
- Answer in the moment, not "later at home." Later means the question was a problem.
- Expect the same question again next month. Repetition is how this age files things.
Avoid this
- "I'll tell you when you're older." Files a simple question under something enormous.
- "Don't look at other people!" Answers a question they did not ask with a shame they did not have.
- A full explanation of reproduction to a child who asked about a shape.
If it repeats
Asked over and over, this is a child checking whether the answer stays the same. Keep the wording identical. If detail arrives that nobody in your house supplied, there is a page on that later.
Why the book suggests this
This is a question about categories, not about anatomy. A child of four is busy sorting the world into kinds of thing, and having just noticed that bodies come in more than one arrangement, they want the rule that explains it.
It is asked in the same tone as "why is that car red," and it wants an answer of the same size. The discomfort in the room is yours. The child has not brought any.
Related prepared situations
What happened next?

From this collection
Same Words: Their Own Body
45 prepared situations in this family area.