Sibling Rivalry Researcher T-Shirts

'I am so proud: My kids are finally fighting all the time!'

Polygamists' Picnic

"He's my smart-aleck twin."

"I'm an oldest child trapped in the body of a middle child."

"Good work Tim, you snatch it all: none of this sharing with your brother nonsense..."

"At home there's a fish, a cat, a dog, me, and a big sister."

It's my biggest project - a database of all my sister's boyfriends.

"We tried to play nicely, but frankly it's not as much fun as tormenting each other."

The noise from the basement was probably nothing – but if it was, she was a sacrifice her older brothers were willing to make.

Help!I am being forced to eat vegetables

"Act your birth order!"

LEMONADE 50 CENTS, 'Sorry, cash only -- we don't accept little brothers.'

'Mum, she pulled my mane!'

"You can't live in our basement. Your brother beat you to it."

'At first I wanted a brother, but I've changed my mind... I want a puppy now.'

'I suppose this puts my new bike on the back burner?'

'Does this mean I have to share my pocket money?'

'MOM! -- Samantha called me names in her diary!'

'How do you expect them to treat you in a mature way with that thing in your mouth?'

"If you have one child you are a parent but if you have two, you are a referee!"

"How many times do I have to tell you to quit going through your little brother!"

"Meet your new baby brother! We decided to upgrade."

'Take it from someone with experience. . . you can't go throwing tantrums until you've at least tossed a few.'

'Mom! - Jeffrey just said a DADDY word!!'

'Stop crying or Mom will think we're not having fun!'

'No hair or teeth, can't walk or talk -- he's kind of a starter kit.'

"Mom always liked you best."

"I'm wearing new cologne. I hope Smiley is able to control herself around me today."

Brother and sister at the dentist

"I was raised as an only child, which really annoyed all my brothers and sisters."