Hi Veronica--I confirm you really need to look at the individuals independently before you check out their synastry. A couple with stressful inter-aspects involving Mars or the Heavies isn't going to errupt into domestic violence if both people come from a background where violence was verboten, where alcohol/drugs aren't involved, and one member routinely chooses the "flight" over "fight" option. I think a lot of spouses/partners feel angry enough to smack their SO on occasion, but most of them are civilized enough not to do it.
We could imagine a man's chart with a tough T-square involving Mars, Venus, Pluto, Saturn, and/or Uranus; but then her Venus conjuncts his Pluto, and her Mars conjuncts his Venus. Trouble is, if some domestic squabble emerges, she reactivates his T-square by virtue of her own placements.
This is not to say "It's her fault." It isn't. Nobody provokes another human being enough for assault/battery to be acceptable. Everyone has non-physical ways to deal maturely with anger.
So far as I know, partners in a violent relationship generally both had childhoods where violence was commonplace. Although there are cases of women being physically violent toward their husbands/BFs; the huge majority of cases are the man being violent towards the woman. He was raised to see Dad take it out on Mom; and she was raised to see Mom put up with it. Oftentimes she suffers from low self-esteem [which you can see in a chart] and fears she has nowhere else to go or that she will publicly look like a big failure if she admits being battered.
Another way this can happen is when Dad abandons his children, and a little girl grows up longing for a Mr. Right who will never leave her. Initially she mistakes her BF's jealousy for devotion. Then he expresses his jealousy in physical violence.
Low self-esteem indicators would be Neptune, Saturn, and possibly Pluto stressing out one of the personal planets such as the sun.
If someone had a crummy childhood, look at their 4th house of early childhood conditioning, as well as their parental indicators [moon for Mom, rulers of IC/DC axis] to get a sense of whether they were an abused child. [This includes children who were not physically assaulted but who had to watch Dad hitting Mom.]
Interestingly, the 7th house is not only "the house of marriage", but "the house of open enemies." You might look for action there. If neither person has planets in their 7th house {or in the composite chart] look at what is happening with the planets that rule the signs on their 7th house cusps.
Veronica--also. If this question is more than academic in your case, or the case of someone whose chart you're reading...the best advice is for the woman to leave and if need be, live in a battered women's shelter. Oftentimes the abuser ramps up the assault over time; and she [and children, if any] wind up seriously injured or dead, if she stays with him. Psychological counseling for all is obviously indicated.
Bitter kind.
