Many people begin relationships with hope and optimism, only to have each of them end without apparent reason. They painstakingly go over every detail, but can't seem to find the clues that explain why or how that happens.

"I don't seem to have trouble attracting partners. In fact, at the beginning of the relationship, they usually tell me they really like me a lot. Then, like clockwork, they begin to slowly pull away, and I haven't done anything different. It's not about not being attracted to each other any more. That's often the last to go. I can't figure it out, but it's really beginning to lower my confidence."

"When I fall in love, I give everything I've got to make a relationship work. Even if my partner doesn't reciprocate perfectly right away, it doesn't matter. I keep thinking that if I do it right, I'll get what I want eventually. I know I sometimes get resentful when I'm doing most of the giving, but I still keep looking for ways to make my partner happy. And they sure seem to enjoy it when we first get together. I don't know why they leave when they're getting such a great deal."

"I think one of the sexiest things you can do in a relationship is have a good fight. Sometimes I argue just to get things more interesting. Most of my new partners tell me that they love my spunk and how I can always see more than they can. I don't know why it can't just stay that way. For some reason I don't understand, they don't want to play the game anymore. It always ends that way."

The similar clue in each of these examples is the person's feeling that he or she has never changed behaviors in the relationship, yet what was once attractive ceases to be. They may emphasize that their partners seemed willing to take their gifts up front but valued them less over time, placing the blame outside themselves.

But what if something else is going on that is harder to see? What if these people are right; that they are doing something in all of their relationships that is, in fact, attractive at the beginning of a relationship yet grows irritating and more unacceptable as time goes by? What if they are sabotaging their relationships without knowing they are doing it, undermining the very love they thought they had secured?

If you are someone who has started relationships determined to love and be loved, given everything you had to make the relationships work, yet watched them slowly fall apart no matter how hard you tried, your own behaviors may be the reason. You may be an innocent, unsuspecting relationship saboteur.

There are many behaviors that attract and repel that way. For example, insecure people may initially attract rescuers who believe that they can heal them if they can just reassure them enough. Those over-giving, over-protective caretakers need to believe their sacrifices will work. But, if the insecurity does not give way to greater confidence over time, the rescuer may eventually lose motivation and search for someone more receptive.

Another example of an attract/repel behavior is the need to control. It usually manifests as micro-managing and can be very welcome to people who procrastinate and flounder. The take-charge person has his or her work cut out for them, and the person in need of being organized feels loved and supported. But, over time, that same controlling behavior can feel oppressive and invasive.

Other examples of relationship sabotaging behaviors are needing to win, pessimism, addictions, martyrdom, defensiveness, passive-aggression, promise breaking, arguing, procrastinating, complaining, exploding, or withdrawing. All of them will attract a reciprocal lover, and continuing them will ensure that the relationship will eventually end.

If you chronically practice any of these behaviors, you may be inadvertently driving your partners away without realizing it or intending to do so. By recognizing and owning your relationship sabotaging behaviors, you are on your way to changing how you behave in the future and ensuring more successful partnerships.

guest blogger Randi Gunther, Ph.D. is the author of Relationship Saboteurs: Overcoming the Ten Behaviors that Undermine Love .