Over on the SoloHQ site, Roger Bissell quoted Rand's statement (in her article, "The Comprachicos") that an infant's chief means of survival was the awareness of emotional vibrations. Roger interpreted her usage to be something along the lines of ESP, as if she thought the emotional vibrations were picked up by senses other than our standard input channels.
I never thought she had anything extrasensory in mind. I always figured she would have said that the baby was picking up sensory cues and integrating them to form an emotional impression at a subconceptual level. Or something like that. After all, if a dog can do it, why not a baby?
What mysterious factor
Allows us to watch an actor
And "get" that he's feeling down
When he frowns?