I'm not sure how much of the information on MNS I fully understand, but I found the connection to Autism (and ASD) rather interesting. (interesting article on the deficit of MNS in autistic individuals at this site, http://www.sciencedaily.com/releases/2005/04/050411204511.htm) If you consider that children with autism have dysfunction with the MNS its easy to make a connection between the MNS and development of social relationships through responding to others with mimicry . Infants who are later diagnosed with Autism respond differently to their parents almost immediately, they don't recognize faces as distinct from objects which could mean that they are not programmed to watch facial expressions in order to mimic them. Parents have reported that their infants did not follow their gaze, but also did not respond to a parents embrace/hold. Instead of imitating the parents embrace and snuggling in, they lay limp which could be interpreted as not mimicking the embrace. I guess what I'm trying to say is in retrospect many parents of autistic children recognize differences in their autistic babies almost from the start of life. If the MNS is responsible for much of the social deficiencies in autistic people, it possibly provides evidence of the existance of the MNS at birth. It could be that the reason that a confident diagnosis of autism can't be made until children are older (6-10) is because either the MNS is still developing, or because the effects of inability to mimic create an escalating problem that isn't fully visible until later.