Radcliffe, 21, and 20-year-old Watson, along with Rupert Grint and Tom Felton, were cast as the leading young stars in the Harry Potter franchise in 2000, and have gone on to star in all the movies since.
Away from their big screen adventures, Watson is currently studying at America’s prestigious Brown university, while Radcliffe has enjoyed stage roles on Broadway and London’s West End.
Isaacs is convinced the secret to their continued success is their grounded start in the Potter movies – and he’s pleased they have avoided the fate of many troubled former child actors.
He tells WENN, “I’ve known some child stars in America who’ve been enjoying films and then the world has really corrupted them because they’re exposed.
“These guys (the Harry Potter stars) have been behind closed doors in this big family at least, making these films for a decade.
“They’re emerging fully formed. They’re adults, they’re grounded, they’re humble, they’re really talented and they’re a tribute to everyone who’s been surrounding them, and their families. They’re old enough and solid enough that nothing will knock them off their feet.”