Did you know if you Google the phrase "screaming children on planes," you get 5.9 million results?
That's either a lot of bloggers who have flown a lot of miles on the last flight home from Disneyworld, or disruptive passengers on planes are a universal problem. I don't mean to pick on screaming children, because as we all know, attached to every screaming child is a parent who is most likely mortified. Are there things that you can do to protect yourself from the annoyance of disruptive passengers?
First and foremost, be polite if you have to make requests of disruptive people. While it's truly tempting to glare, furrow your brow, and release a disapproving sigh in the direction of a person, be it child or adult, when they are not behaving in accordance with your norms for social manners, this does little to resolve the situation except to make you look grumpy. Try first to be part of the solution.
With disruptive children
If a child is misbehaving, like kicking the back of your seat or (as happened to me today for 2 hours) you, take a deep breath and if they're traveling with their parent, smile and say, "I'm sorry to bother you, but could you help me out with asking your child not to kick me." Choose your battles on this one. If it's just a fidgety kid who isn't doing anything malicious but can't sit still, and it's a minor annoyance versus intentional, you may help provide the parent with a degree of relief by just dealing with it.
If a child is bored, you can always try talking to them. Sometimes, talking to a stranger will prompt them into behaving.
With crying, disruptive children
Flying can be terrifying for small children, and there is nothing that will console them. Your best bet to deal with this situation is a good pair of headphones. I've found that these JBuds J3 Micro Atomic In-Ear Earphones with Travel Case (Titanium Silver) work wonders on planes. Great for noise cancelling and they don't take up very much space in your carry-on.
With disruptive adults
Dealing with difficult adults can be risky, especially on a plane. In some cases, people may have been drinking before they got on a flight and then ordered more when the cart went through. If someone is being loud, see previous note about headphones. If they're being silly and loud, usually just a well meaning "Hey, do you know that the whole plane can hear you right now?" will quash their volume. If someone is doing something that is just bad form, alert the flight attendants. That's what they're there for.