If we describe something as unethical or immoral, it's generally some kind of event or action we are referring to. An adult verbally or physically abusing a child, for example. There's the actual act of abuse and there is the impact that abuse has on the victim. That impact is based on the conscious experience of the person being abused. That conscious experience is based on activity in the brain.
If we had a more thorough understanding of brain functionality, to be able to see how verbal or physical abuse impacts the victim, we would have an objective, scientific basis for saying that abuse, even verbal, is immoral or unethical.