Bradley Cooper's acting family

Bradley Cooper says Robert De Niro and Jennifer Lawrence are like "family" to him.

The 41-year-old actor reunited with his former co-stars again on their latest movie 'Joy' and he enjoys collaborating with people he has previously worked with because it is so comfortable.

He said: "Bob and I worked together on 'Limitless' so we had become friends and I met Jen on 'Silver Linings Playbook'.

"It feels very much like a family when you make movies with the same people."

And the 'American Hustle' star is always blown away by 25-year-old Jennifer's talent.

He said: "She's an incredibly actor who is very gifted and perfect for just about any role.

"That's a rarity - and she's just so young."

Despite his own years of success, Bradley admits some of it can be attributed to pure luck.

He said: "It's a mixture of hard work and luck. I'd be a fool to say I haven't been very lucky, though I do work very hard."

But he also admitted he has a lot of "doubt" about his abilities.

He told Britain's Star magazine: "There's something deep inside me that has given me the traction to be able to push forward.

"There has to be a deep belief in oneself, but with that comes a lot of doubt."