Recently I had the pleasure to meet with Marsha Podd, R.N., C.L.E. author of Secrets of a Baby Nurse. We met up because of a mutual interest in infant sleep and well being. During our conversation we discussed sleep training. Marsha works with parents of newborns on sleep training. She and I discussed our personal belief in infants learning to sleep on their own. Learning to self-soothe and self-regulate is an important skill that can be learned as early as 6 months old.
Marsha also mentioned a study that was done that followed up with children at six years of age that participated in sleep training. What they found is that 'controlled crying' and other sleep training methods had no adverse behavioral or emotional affects as compared to those who had sleep problems, but received no training. In fact, the study comments' "without intervention, sleep problems are more likely to persist into childhood, potentially leading to behavioral and cognitive problems including aggression, anxiety and attention and learning difficulties". You can read more from Murdoch Children's Research Institute here.