Does Love Exist? Science has the answer

Attachment 
Attachment involves wanting to make a more lasting commitment to your loved one. This is the point at which you may move in together, get married, and/or have children.  After about 4 years in a relationship, dopamine decreases and attraction goes down. If things are going well, it gets replaced by the hormones oxytocin and vasopressin, which create the desire to bond, affiliate with, and nurture your partner. You want to cuddle and be close and share your deepest secrets with her. You plan and dream together.