Literature and research describe several types of styles in relationships. These styles or categories were initially inferred from observational research on children. Later adults were interviewed as well to find out that people develop or have certain attachment or relationship mindsets they bring into relationships. These attachment mindsets have certain thoughts, behaviors, and feelings connected to them and they affect the way one relates in very close intimate relationships. The way we talk about these styles may make them seem rigid and unalterable. But personally, I like to think of these categories as somewhat flexibly. What I mean by this is one can change his or her style depending upon different internal and external variables and experiences in relationships.
The second mindsets two are considered insecure. They are ambivalent and avoidant. The internal thoughts and feelings that dominate a person who is ambivalently attached sound like this, "Why aren't you, the other, there for me? Am I really important to you? I am not okay but you are. If I were good enough, you would be there for me when I need you. There must be something wrong with me. I feel afraid, lonely, and anxiously focused on the relationship. Yelling and protesting does not seem to make you love me." The avoidantly attached internal self-talk might look like this, "I have to take care of business on my own. Relying on others is a weakness. If I really put myself out there, I will not be accepted anyhow. It is better to keep things to myself, avoid conflict, and be self-reliant. Bringing up needs or issues just causes fights." With both of these insecure styles, there is distress and feelings of loneliness in the relationship because the parties cannot figure out how to reach and support each other. People often get suck in a negative pattern feeling there is no way out.
For more on this negative pattern read Dr. Karen Shore's handout: The Negative Cycle.
For ways to identify and start changing your attachment dynamic (by Dr. Shore):Our Negative Cycle: Let's Break It!
For more on attachment see: Ask.com.
Find Your attachment Style