On another point, I would point out that in general adults are very, very attuned to having emotional responses to crying children (the younger the more powerful the response), whether we have our own children or not. That's why a baby crying on a red-eye flight can have such emotional reactions from total strangers (often negative, unfortunately). It's a wonderful human instinct that I think serves us very well in general. But those who aren't experience parents need to remember the following (_please_):
* Every baby has a different temperament and personality.
* Babies sometimes cry to get attention and not because they are actually in any way uncomfortable or scared. The different sounds are easy for the baby's parents to hear and difficult for other people to distinguish. (as mentioned, newborn infants are easier in that they always have a reason when they cry).
* They sometimes cry for a while and there's nothing you can do. Seems to always happen in public. Leg aches, colic, gas, etc.