Answer: Expressiveness
Explanation:
Expressiveness is the tendency to conveying any thought, feelings,idea , emotion ,action or value in effective manner so that other can understand it.Clear expression induces the actual meaning behind the thought or words of any person.
According to the question ,expressiveness maintains harmony in family as family members are aware about the feelings and thought of each other which handles their emotional understanding and internal affairs.
According to Philip R.Shaver, there are three "behavioral systems" that play a role in romantic love: attachment, caregiving and sexual attraction.
You view love as an attachment when you are emotionally dependent on the other person for your happiness, safety and security, while love as caregiving refers to the great pleasure you receive from supporting, caring for and taking of a loved one.
Lastly, love as a sexual attraction is when you can't get the other person out of your mind and the thought of him or her excites you and turns you on.
If we will based the statement above from Shaver's model, we can say that the love being felt by John and Cynthia for each other transcends from attachment love to caregiving love.