Jessica Biel says the secret to her successful 10-year relationship with husband Justin Timberlake is them both being "career-focused".

The 35-year-old actress - who has two-year-old son Silas with the 'Can't Stop The Feeling' singer - says the pair are both dedicated to their work and she says being "selfish" has allowed them to maintain a strong bond.

Speaking to the US version of Marie Claire magazine for their sustainability issue, she said: "We have similar values; we believe in loyalty, honesty. We like to have fun. We like a lot of the same things.

"Also, in the business, we're all very career-oriented, and you have to be a little selfish. I understand that about my peers- about being focused and driven - and if you can find that and someone who shares the same values as you, it's like: Score!"

Jessica says she has grown to be "selfless" since the arrival of their baby boy.

She said: "You think you're a selfless person, and then you realise you're not. These little people come around, and they require so much, and your schedule is really not your own, nor is it important anymore, and it's very clear that it's your life now revolving around this dude.

"I'm not that person who feels like, 'Oh, my whole life changes for my kid,' but it does."

Despite admiring her 36-year-old spouse's work ethic, the 'Sinners' star recently confessed she doesn't want her son to be a musician like his father.

She said: "There's one thing I don't want for him. I really don't want him to be a musician. I know what you're thinking. Good luck to me, right?'

"I watch what Justin goes through and he is at the top of his game. He has access to work with any producer and he can actually get songs on the radio. And, this is from someone who makes great music - he tours and makes it look very easy. But he's been working for years and years and years to get to where he is."