Gwyneth Paltrow's secret to a happy marriage

Variety may be the spice of life, but Gwyneth Paltrow thinks otherwise when it comes to a happy marriage.

The Oscar-winning star credits her happy nine-year marriage to Coldplay frontman Chris Martin to their similarities - both as people and as creative types.

PHOTOS: MTV Video Music Awards

She told US InStyle magazine:

"We laugh a lot, and at the same jokes. We like the same music and we like to do the same things."

GALLERY: Rock star daughters!

Gwyneth with little Apple watching her husband Chris Martin in the crowd at Live 8 in 2005. Source: Getty

But sometimes sharing creative tendencies isn't all it's cracked up to be, the 39-year-old Shakespeare in Love beauty admits:

"Our artistic temperaments together [is the hardest part]. Artists are sensitive. There are ups and downs, mood-wise. Musicians need a certain gravitas and focus in order to write.

RELATED: Gwyneth Paltrow's stylist reveals what hidden in the star's closet

"The temperament that goes with someone who is creative can be challenging."

The star also opens up about her kids - including her strict TV rules and her experience with postpartum depression after her second child Moses, now 6, was born:

“I only let them watch TV in French or Spanish. When I’m in France, I go to [Boulevard] Beaumarchais and buy all their cartoons.”

GALLERY: Best & worst post-breakup celebrities

Chris Martin on stage in 2009. Source: Getty

“When Apple was born, she had the hugest blue eyes. I looked into them, and she was looking at me, and I felt like, You are here to teach me everything.

"After [Moses] was born I had postpartum depression. It was a difficult time, and because of that I believe I have an extra empathy for him, and he for me.”

PHOTOS: Gwyneth Paltrow back on the red carpet

On having another child, Gwyneth says: “My brain says, ‘Oh, I think I’m done, the kids are so big now, and I don’t want to go back to changing diapers.’

"But a part of me would love to have another. Of course, I’m old now!”

_