From going to playgroups etc, I have noticed that parents who appear to genuinely enjoy & interact with their kids have much better behaved kids. Its the parents who are constantly bickering & reprimanding their kids over every little thing that have the unhappier, crazier kids.
I commented to one mom about how her kids were so well behaved & she replied kids are kids so she expected a bit of bad behavious. Do some parents just expect too much from their toddlers(me included) & when they don't comply our reactions just make the behavious worse by trying to micromange?