Some children can co-exist with each other effortlessly. But for children with opposite temperaments, sharing a room can create more conflict than you can handle. Is one child a noisy night owl? Is the other an early-to-bed, early-to-rise child? Is one child neat while the other is messy? Your children's temperament fit will be important considerations as you make family decisions about room-sharing.

Perhaps the biggest drawback to sharing a room with a brother or sister relates to issues of privacy. Older children care about having time alone as well as space to themselves. Loss of privacy when friends are over can be another source of conflict.

The Toss-up

None of the downsides have to change your decision to put your children together. Just remember to factor each negative into a plan for making the room-sharing experience more positive. It can certainly make the bedtime routine easier when young children, especially same sex siblings, share a bedroom, but as your kids get older, the privacy issues can render sharing a bedroom particularly difficult. If your children are older, include them in the discussion about whether to share a room or strike out on their own. They know best whether or not their friendship can stand the test of close quarters. Sometimes a weekend sleepover in each other's rooms may be all either you (or they!) can handle.