How exactly did Chihiro guess it right in Spirited Away?

Question

In Spirited Away, the witch Yubaba gives Chihiro a puzzle so that she and her parents go back to human world.

In the puzzle, a herd of pigs, that may or may not contain her parents, was presented before her and she was asked to identify her parents. After a while, she guessed that her parents weren't among them.

This raised a question in my mind.

How exactly did she find it? She just paused for a while and guessed accurately. Is there any clue or plot-point I missed?

Answer 1

It's a combination of two things:

• Chihiro has a natural aptitude at seeing through appearances - the polluted river spirit, No Face's offers, Haku's dragon form. This is actually a frequently recurring theme, with Sen's good heart and lack of greed letting her see people for what they really are, while Yubaba does not recognize the fake gold, the fake baby, or the real baby.
• I believe that the headband charm which Zeniba gave to Chihiro just before she left further increases this ability, and Zeniba made it just for that purpose. There are some hints:
  • She only just made it.
  • Right afterwards, Haku arrives and Zeniba remarks "good timing", which can be interpreted to mean that it was important to finish the headband and give it to Chihiro before she leaves.
  • The very next thing Chihiro does is discover Haku's real name by remembering how she fell into the river.
  • And then she sees through Yubaba's ruse and recognizes that her parents are not among the pigs.

Finally, Yubaba acts pretty damn smug when she states the puzzle. It doesn't take a genius to suspect that she's not playing fair, and then the way for her to cheat is not hard to guess.