Instead, the renowned political interviewer and chair of the BBC's Question Time would provide the child with a list of objects, such as a worm or a rusty nail, and suggest that the pair look for them together.
"If you say, let's go for a walk, they'll say, bo-oring," he said, whining plaintively on the final word. "You need to involve them, to make the world interesting."
The same principle, he believes, underlies the new Schools' Question Time Challenge, a nationwide competition he launches next week that aims to inspire youngsters to take an interest in politics, The competition asks 14 to 19-year-olds to submit proposals for a political discussion event at their school, based on Question Time - including panellists from their school or local community, a chair and a list of issues to be discussed.
It is supported by the Institute of Citizenship, of which Mr Dimbleby, 65, is president.
Mr Dimbleby said: "Of course, young people are self-obsessed, and more interested in clothes and music than anything else. "They're disaffected by Westminster politics, because it tends to concentrate on personalities, and the personalities aren't particularly interesting.
"But pupils pick up on issues that matter to them: bullying, drugs, truancy, the war in Iraq. Their instinct is to be provocative. They will push an argument to the end and won't accept that things can't be changed."
The Question Time format will enable teenagers all over the country to take part in structured debate about issues that concern them.
Mr Dimblebey hopes this may show them the relevance of party politics.
"They will learn how to come up with a logical argument and not just blather on about their prejudices. It shows them that there is a process there. If you engage with it, you can channel your outrage."
Proposals from pupils should be submitted by January 7. Twelve sets of finalists will then be presented with pound;500 to support the staging of their debates.
Judges will visit each shortlisted debate, and select four winners. These winners will be invited to produce a real Question Time programme, to be screened on BBC1 next summer.