A man looks at a photo and says: “Brothers and sisters I have none, but that man’s father is my father’s son.” Who is in the photo?

How to think about it

1. Start with the fact given up front: the speaker has no brothers or sisters.
2. Now unpack “my father’s son”. The speaker’s father has exactly one son, because the speaker has no brothers. That son is the speaker.
3. Replace the phrase: “that man’s father is me.”
4. If the speaker is the father of the man in the photo, the man in the photo is his son.

Why “his son” is the answer

Because the speaker is an only child, “my father’s son” can only mean the speaker himself. The sentence then reads “that man’s father is me”, which makes the man in the photo his son. People often answer “himself” because they stop one step early, before applying the word “father” to the result.

Common wrong answers

• Himself. This is the most common error. “My father’s son” is himself, but the riddle says that person is the father of the man in the photo, so the photo shows his son.
• His father. His father’s son is the speaker, not the speaker’s father.