Undoubtedly and unequivocally, yes. Without compassion, care, love we're empty shells. Hallow husks of flesh and bone, if you like. A harmonious and welcoming atmosphere gives us power in various forms.
1. It strengthens our immune system and our body - if you happy, you are less susceptible to various diseases, especially aging and heart diseases
2. It strengthens our mind - if you are happy, your mind is clear, it is stable, it is stronger. People, like other beings, learn to do things by rewards, having a family gives a person reason to live, reason to fight and more important of all, it gives said person LIFE
3. It softens the character and brings wisdom into our life - every person is born without any hardship and negativity, those sentiments, feelings if you like, are gained over time, through bad experiences. Having love in ones life, helps us dilute those bad memories and set those feelings aside. Love actually makes you a better person and teaches you the value of freedom, the knowledge of wisdom and in one way or another, the meaning of life, well part of it at least.
So in order to answer your question, yes. Monogamous life is very important to us, it is the only thing that will help us go to the next step.