symmetric relationship

What factors seem to be important in influencing how symmetrical the relationship (man/woman) is? (Daisy, Maria, Wendy, Mary and Elvira)

---In my opinion,symmeticical relationship is a difficult situation to achieve.From a macro-view,it exists where the male and female have the same background,status,rights and share the same role in the work or society.If we classify this carefully,it goes to the similar interests,charateristics and the living habits.
But in fact,a lot of people prefer the other relationship between the male and female which is called complementary. (http://answers.yahoo.com/question/index?qid=20081108155100AAtaGHr )
Some other things about symmetical relationship between male and female in violence.Early research by Straus, Gelles, and Steinmetz (1980) suggested that males and females perpetrated intimate partner violence (IPV) at similar rates,These studies, conducted primarily with college and high school students, measured both perpetration and victimization among males and females (Arias, Samios, & O'Leary, 1987; Makepeace, 1986; Thompson, 1991; White & Koss, 1991). An accumulation of results from a broad range of samples (e.g., Cantos, Neidig, & O'Leary, 1994; Capaldi & Crosby, 1997; Umberson, Anderson, Glick, & Shapiro, 1998) suggests IPV is usually bilateral.