Without missing a beat, Olivia replied, "I am not being a contrarian!"
Olivia's not really disagreeable -- she's just a typical preschooler learning how good it feels to assert herself. "Kids this age don't know how to speak up for themselves respectfully, so their words come out more aggressive than assertive," says Mary Sheedy Kurcinka, author of Kids, Parents, and Power Struggles.
To help your own child be a little more diplomatic:
Don't take the bait. Instead of arguing, say, "That's a different perspective." You can also ask why she feels the way she does: She may hate the red turtleneck because it's itchy. If it seems like she's disagreeing just to see how it feels, move on, for your own sake.
Put words in her mouth. "Show her how to say what you think she's really trying to get across," says Kurcinka. When she argues over what's on her lunch plate, for instance, you might say, "Hmm, how can we work this out? What if you have an apple too?"
Take a nap. If your child's vocabulary has shrunk to the single word "no," it's not a plot to get you; she may just be tired.
Have some laughs. If you say, "Wasn't that a nice day in the park?" and your child says, "No, it was an awful day!" you can turn the situation around by agreeing -- in a humorous way -- that the sun was too bright, the grass too green, and the sandbox too, well, sandy.