Well, as relationships start, you become closer the more you communicate.
After a point, however, the quality of the communication is what the closeness depends on.
Finally, when you are extremely close, it really doesn’t matter how much you communicate with them because you know them so well that whenever you meet up, you can connect instantly.
Once you’re at that point, you may not want to have long gaps between communicating, but they usually won’t hurt the relationship unless they are unexplained.
You need to communicate frequently at the beginning of the relationship to start forming a real bond with a person, but doing things together is usually also a part of this. (That’s why we usually form relationships with the people we see or interact with often.)
After you form a bond with a person, and you can call them your friend, you need to work on communicating with more depth and meaning because otherwise the relationship is stuck in the “chit chat” stage and you never really get to know each other.
Once you have started to understand each other and really know what’s happening in their life, well, it’s natural for people to get a base understanding of the other person: a glimpse into who they are, deep down. Usually this comes from sharing secrets and being intimate, in sexual ways or otherwise.
After both people are confident in their relationship to the other person, and you both have a good grasp of the other person deep down, the need to communicate frequently is a lot less, and that’s when you get couples or close friends who can spend an evening together without talking at all, but they still have a great time.
Hope that helps! ^_^