What happens if your child makes it as an actor? If they move past the audition rooms onto the stage or in front of the movie cameras, the chosen one, plucked from the crowd for potential stardom?
Will your kid be like Daniel Radcliffe, who won the role of Harry Potter at 11, gaining fame, fortune and a successful transition to adult roles? Or more like another Jewish child actor, Canadian Corey Haim, a teen idol in the 1980s, who died destitute at 29, having lost his career and millions to a drink and drug habit, triggered, it is claimed, by sexual abuse from older men in Hollywood.
I talked to child actors, parents and a film set chaperone to research my latest novel, Cuckoo, which is about a 16-year-old soap star whose promising career crashes when the character he plays disappears into his bedroom for six months, putting his career on ice.
I expected to find stories of burn-out and substance abuse, Hollywood-style. I didn't. The world of a successful child actor in the UK is one of hard work and premature responsibility.
My main interviewee was 19, and had been working since he was six, starting in adverts and progressing to main roles in feature films. He decided to swap his agent at 12, preferring to go with another agency who he felt would help his career better.
He paid his own school fees - child actors do better at private schools, because they can negotiate time off during term time, which is now nearly impossible at state schools.
He did well in his GCSEs, but left school without taking his A levels, because a television role came up that meant living away from his family in a strange city for nearly a year. That was a decision that he made for himself, he seemed vaguely surprised at the idea that his parents might have insisted on his taking his exams.
Switching between acting, where he felt like an adult, and school where his friends felt much younger could be difficult. So was dealing with rejection - "You learn very early not to take it personally"- and waiting for roles to come up.
The most difficult time for child actors is their late teens. Suddenly the roles dry up, or go to young-looking adult actors. This week, the new Harry Potter play opened. The main child roles are taken by actors in their twenties.
I talked to one father who encourages his daughter to audition for musicals, to boost her self-confidence. "She's got emotional problems, and feeling like a star, getting those roles, it's good for her. She believes in herself."
But drama school teachers warn that mental health problems are rife among students. Many vulnerable children find acting is an escape from the pressures of being themselves, they prefer to take on other roles than face up to their everyday problems. But when the play or film or television programme is over, they find it difficult to cope.
As the Spielberg audition showed , there is always a ready supply of children looking to step into the spotlight. Some may become stars. But the vast majority will never be picked, or have showbusiness careers more like that of the JC's editor, Stephen Pollard.
Recruited by a lady in Stanmore ("I think she was called Stella") aged around eight, he played - "for about 10 seconds"- a rapidly ageing boy in British science fiction series Space 1999. He also sat around a campfire with Christopher Biggins, advertising Green Shield Stamps ("I was directed by Ridley Scott"), listening to another child try and fail to master a four-word line.
That was enough. Acting's loss was journalism's gain.
