Katie -- were the answers I wrote OK?  You never gave me any feedback.  If
you need/want me to elaborate them or alter something, just let me know, I
won't be offended.

On the topic of baby wearing, mother nature/evolution/God doesn't publish in
the peer-reviewed journals (not that there could be one for God!!!), but all
the non-human primates practice "baby wearing" as baby primates are not able
to get up and locomote on their own right after birth the way horses and
cows can.  Some of the 'lower' primates, such as prosimians, do build nests
in trees and leave (cache) their babies for several hours at a stretch while
the mother goes out to feed - the way dogs and cats and birds do in the
wild.  But all of the monkeys and apes carry their babies on their bodies.
The classic research done with monkeys (forgetting the name of the
researcher right now) showed that monkeys taken away from their mothers and
offered either a cloth mother without food or a wire mother with food,
preferred the cloth mother.  And that they grew up very neurotic and
anti-social.  When they redid the experiments with two different cloth
mothers, one cage with a cloth mother who moved around inside the cage and
one cage with a cloth mother who was stationery, the monkeys on the moving
mother turned out *less* neurotic and anti-social than the monkeys on the
stationery mother (though still not normal, by any means).  Obvious, both
clinging to the mother and having the mother move around while the baby is
attached are important experiences for all higher primates, including
humans.  Just like breastfeeding and co-sleeping, these are suites of
behaviors that have evolved over many millions of years (more than 40
million for the higher primates).  Natural selection has acted to keep those
behaviors that contribute to reproductive success, and elminate those
behaviors that are harmful to the children.  NONE of the higher primates
leave their babies in nests -- they ALL carry them on their bodies for many
months/years.

Kathy Dettwyler