If you are talking about emotional damage before a child reaches the ability to interact verbally, then no, I don't know too much about that.
There isn't much research out there to know much about it. Lots of theories. Very difficult to test it however. This is due to the idea that we don't map many memories in this phase of development - and the theory behind this is that because we don't have language (oral language, that is), we lack a means by which to map these memories in a structured format, thus losing many of these very early memories and/or the ability to make much sense of them other than a sort of global cognitive-order making rule-system sense.
For example, in the pre-verbal phase, we are sort of making hypotheses about many things in the world. The lights come on in the room. We wonder, "the lights came on....I turned my head...I made the lights come on by turning my head..." so we turn our heads and the lights don't (or maybe they do!) come on again, and we make new hypotheses based on that. Some things prove true, others false, and we develop ideas and rules based on these ever-increasing and extremely rapidly developing ideas. The rate at which these things happen is so phenomenal it is mind-boggling! The language development rule-system in itself is just tremendous - from the standpoint of how it interacts with cognition, the ties are quite complex.
The emotional system then plays into both cognition and language, as well as social development which also intersects these. So, the studies are - difficult - to say the least. The problem is that it would be more done on single case studies, and small groups, because it is very difficult to study larger population sizes for obvious reasons. And to tease out so many factors (economics, nutrition, two which come to mind immediately, and others cited in the literature).
But, really I don't know much. Do you have a specific question? I might be able to find something for you.
