Kim Kardashian reveals why she won't smile: 'It causes wrinkles'

The world has finally learned Kim Kardashian's anti-aging secret. The Keeping Up With the Kardashians star revealed that she rarely smiles and laughs "on occasion" as it supposedly doesn't do youth any favors.

On Instagram, the 34-year-old mom of North captioned a photo of herself laughing with a friend: 'See I do smile... even laugh on occasion. Not too often though because it causes wrinkles."

A photo posted by Kim Kardashian West (@kimkardashian) on Dec 12, 2014 at 1:31pm PST

While the comment was likely meant to be tongue-in-cheek, there seems to be a kernel of truth to Kim's anti-aging philosophy. She generally gives the camera a more sultry, serious pose and is more likely to channel Zoolander than say happy-go-lucky Christie Brinkley in the '80s.

Even her husband Kanye West, 37, seems to prefer a more apathetic demeanor in public. The two have often been spotted on the red carpet with their sexy, non-smiling poses.

Perhaps that's what makes them the perfect match?