If a daughter was exposed to her mother being beaten by her father from before she can remember, is she still affected?

sometimes it can effect people in unusual ways, such as losing trust in others, look at Erriksons stages of psychsocial developement and read the section on trust vs mistrust

it all depends on the temperment and personality of the little girl

You could also take a look at Attachment Theory.

http://en.wikipedia.org/wiki/Attachment_theory

Most of it is centered on infancy to age 2.

No. If she can’t remember it, she can’t remember it. Your brain isn’t really set up to form memories that early (and if they are formed, they are almost certainly not retained).

Memory isn’t the only way that history can be carried forward in a person’s life. If there was emotional trauma, like fear, inability to feel safe, inability to emotionally connect/attach to her mother—those things could easily have easily resulted in emotional habits and tendencies that carried forward, even though the literal memories are gone.

@Mangus: Emotional memory circuitry is also not formed by that age. Your brain is too underdeveloped and goes through too many changes for there to be any substantial residual effect. Trauma is learned, fear (with a few exceptions) is learned, attachments are learned.

The only thing you mentioned that I believe could be impacted at that developmental stage would be attachment. But the question asked whether witnessing abuse could affect the child, and I don’t see any overt relationship between witnessing abuse and attachment to the mother. (Attachment to the abuser would be a different story).

I’m confused. If we don’t have memories from the age of 2, and we don’t have emotional memories from the age of 2, then how can we talk about development at that age? Walk, talking, etc. Why would it be possible to remember how to talk, learn how to walk but not have memory and emotional memory “circuitry? Also, how does this view account for personality features/quirks that are observable in the 1–2 year range that carry forward? Are those only genetic then?

I should clarify: I don’t think it’s a question of whether she “saw” it happening. I think it’s a question of whether she was in an environment where that was happening. The chances, to me, seem very slim that the home environment wasn’t dramatically problematic (the beating being both cause and effect, related to the whole situation). And she was living in that dysfunctional environment. Home life, even for 2 year olds, is a whole thing, with many interrelated parts and dynamics. If it was poisoned that heavily, then I think she would be affected.

Walking and talking are a different kind of memory known as procedural memory. This kind of memory is encoded primarily by a brain structure known as the cerebellum, whereas memory for events is encoded by a structure called the hippocampus. The hippocampus is much more vulnerable to forgetting and does not get good at remembering things until around age 3 and then suddenly gets very good at it.

Quite possibly, yes. We remember things from before the time when we acquire language. Some people seem unaffected, however. But Attachment Disorder and other difficulties can arise from such early scenarios.