Negotiation comes naturally to a kid. If you're a parent, I need say no more. For all the non-parents, newsflash: Bargaining with that cuddly loving 'slice of heaven' child is torture because the last thing you'd expect is to have to deal with a pro.
Here are some - inborn? - tactics that my son has been using for the past two or three years (professionals, heads up!):
Appeal to a separate authority - often granddad, grandmum or the other parent (sometimes Nicky ropes in his 3-month old sister as a last resort; obviously he understands the thing about "balance of power" even if he can't quite define it yet)
- Say No from the start - forcing you to backtrack, throwing you off balance; notice how it's EASIER to keep saying No as opposed to finding new ways of encouraging a Yes?
- Persevere, persevere, persevere - when he wants a Yes, he too knows about switching personalities and approaches, repeating the same request a dozen times in as many seconds, wearing the other party down (with shades of Luke 18:1-8?)
Set the terms and conditions - see no.2, Nicky also doesn't often let me get away with making him submit free-of-charge; he usually demands a 'fee' as part of the deal. Makes you wish there were more chapters on Bartering in child-raising books, eh?
- Go CUTE mode - turn up that pout, speak softly and gently to get more people (incl. the separate authorities) to go awwwwwwww... seek pity points and leech on the sheer sentimentality of others!
- Go BERSERK mode - they somehow came across the parents' manual and memorised that part about parents getting tensed up when their kids go nuts, not to mention the Conclusion : When parents are tense, consent follows easy.
Keep the list going if you can. I'm making notes to secure that next million-dollar project...