Attachment parenting is a relative newcomer as a parenting style. It was developed in the late 1990s by Dr. William Sears and his wife, Martha. Their work was based upon the earlier study of "attachment theory" by John Bowlby, which stresses the importance of child bonding, achieved through lots of direct physical contact with at least one parent.
The goal of attachment parenting is to become highly attuned to a child's needs and maintain this closeness as a child grows and develops. This form of close bonding starts as soon as the child and mother are able to be together following birth (even if there's a delay due to medical issues or a difficult pregnancy).
This parenting style places great importance on breast-feeding in the belief that this is the most natural and intense early bonding experience for a mother and child. Another important aspect of attachment parenting is baby-wearing, in which the mother (or father) straps the child to her body using a harness, vest or any number of other devices. Bonding also occurs through co-sleeping, which is when the parents sleep in the same room as the child, sometimes even in the same bed.
So why does bonding have such importance in attachment parenting? This parenting style promotes the belief that discipline is best achieved when you fully know your child and your child fully trusts you. As the child ages, the terms of separation are negotiated between parent and child, and boundaries are slowly pushed outward. (This can be as simple as explaining to your child that you're dropping him or her off with a relative for the afternoon so that you can run some errands, but you'll be back.) This begins to foster independence and self-confidence in the child.
Being a fairly recent arrival on the scene, there's not much in the way of long-term studies for attachment therapy. Though it has many fervent believers, there is also concern that attachment parenting produces kids who are overly dependent and parents who are exhausted from setting such high expectations for themselves as constant nurturers. But, again, there aren't long-term studies to support either opinion.
If you root for the underdog, the next parenting style may not be for you.