Goldie Hawn and Kurt Russell haven't married because they want to preserve their "independent thinking".

The Hollywood stars have been together for 40 years and have son Wyatt, 37, but never formalised their union and the 77-year-old actress - who was previously wed to Gus Trikonis from 1969 until 1976 and Bill Hudson from 1976 to 1982 - explained she likes the idea of having the choice to stay in her relationship.

Speaking on 'Who's Talking to Chris Wallace?', she said:

“I like the idea that I can wake up in the morning and make decisions every day if I want to be here.

“I mean relationships are hard. They’re not always easy. There’s all kinds of hurdles we go through. There’s things that we believe in, things we don’t believe in, we agree on.

“So I think ultimately staying independent with independent thinking is important, so you can hold on to yourself, and you can actually have that feeling.”

The 'Death Becomes Her' actress admitted both she and 72-year-old Kurt - who has son Boston with ex-wife Season Hubley - have seen how "ugly" divorce can be.

She said: “When it doesn’t work out, it ends up to be big business.

“It’s always ugly. Somebody actually has to take a look and say, ‘How many divorces actually are fun? How many divorces actually don’t cost money? How many divorces actually make you hate the person more than you did before? How many divorces have hurt children?’”

Chris pointed out: “But [you and Kurt have] been together 40 years, you’re not going to get divorced."

Goldie - who has actor children Oliver Hudson, 46, and Kate Hudson, 44, with Bill - replied: “How did you know that then?”