If you have more than one child, you are probably already aware of the birth order theory which expounds that one's place in the family is just as important as one's genetic blueprint. Experts seem to have a differing opinions on which birth place means what (if anything) but from my informal, playground straw polls, it seems that the real experts - us mamas - have got it nailed. Because we are the ones for whom the very worst behaviour is saved, remember?
The bottom line is that all children want attention from their parents. The more kids there are, the harder this is to grab and so the more inventive a child needs to be to succeed.
This is how it plays out (at least in my family):