Posted without comment, excerpts from Wikipedia’s article on the psychology of Attachment in adults:

Secure Attachment: Securely attached people tend to agree with the following statements: “It is relatively easy for me to become emotionally close to others. I am comfortable depending on others and having others depend on me. I don’t worry about being alone or having others not accept me.”

Anxious-Preoccupied Attachment: People who are anxious or preoccupied with attachment tend to agree with the following statements: “I want to be completely emotionally intimate with others, but I often find that others are reluctant to get as close as I would like. I am uncomfortable being without close relationships, but I sometimes worry that others don’t value me as much as I value them.” People with this style of attachment seek high levels of intimacy, approval, and responsiveness from their partners. They sometimes value intimacy to such an extent that they become overly dependent on their partners—a condition colloquially termed clinginess. Compared to securely attached people, people who are anxious or preoccupied with attachment tend to have less positive views about themselves. They often doubt their worth as a partner and blame themselves for their partners’ lack of responsiveness. They also have less positive views about their partners because they do not trust in people’s good intentions. People who are anxious or preoccupied with attachment may experience high levels of emotional expressiveness, worry, and impulsiveness in their relationships.

Dismissive-Avoidant Attachment: People with a dismissive style of avoidant attachment tend to agree with these statements: “I am comfortable without close emotional relationships. It is very important to me to feel independent and self-sufficient, and I prefer not to depend on others or have others depend on me.” People with this attachment style desire a high level of independence. …Some may even view close relationships as relatively unimportant. Not surprisingly, they seek less intimacy with relationship partners, whom they often view less positively than they view themselves.

Fearful-Avoidant Attachment: People with a fearful style of avoidant attachment tend to agree with the following statements: “I am somewhat uncomfortable getting close to others. I want emotionally close relationships, but I find it difficult to trust others completely, or to depend on them. I sometimes worry that I will be hurt if I allow myself to become too close to others.”

…secure attachment styles are by no means a guarantee of long-lasting relationships.

Nor are secure attachment styles the only attachment styles associated with stable relationships. People with anxious-preoccupied attachment styles often find themselves in long-lasting, but unhappy, relationships. Anxious-preoccupied attachment styles often involve anxiety about being abandoned and doubts about one’s worth as a relationship partner. These kinds of feelings and thoughts may lead people to stay in unhappy relationships.

…Differences in attachment styles influence both the frequency and the pattern of jealous expressions. People who have anxious-preoccupied or fearful-avoidant attachment styles experience jealousy more often and view rivals as more threatening than people who have secure attachment styles. People with different attachment styles also express jealousy in different ways. One study found that:

“Securely attached participants felt anger more intensely than other emotions and were relatively more likely than other participants to express it, especially toward their partner. And although anxious participants felt anger relatively intensely, and were as likely as others to express it through irritability, they were relatively unlikely to actually confront their partner. This might be attributable to feelings of inferiority and fear, which were especially characteristic of the anxiously attached and which might be expected to inhibit direct expressions of anger.”