Anxious attachment develops when caregiving is inconsistent, unpredictable, and misattuned. These caregivers tend to be more aware of their own needs than the needs of their child.
This leads the child to cycle between seeking comfort from their caregiver to pushing them away. As the child grows, this develops into a love/hate dynamic. These children tend to develop beliefs that they must exaggerate their needs to ensure they get the help they need.
In adulthood these individuals tend to have a negative image of themselves and to be preoccupied with their own flaws, and also a high level of anxiety in general. They worry a lot about their relationships, tending to analyze and over-think the meaning and motivation behind what others say and do.
Their working model of relationships is that they must be vigilant and attentive to relationships to get their needs met, because they cannot trust others will be there for them when they need it (just as they could not rely on their parents to meet their needs.
For anxiously attached adults, the idea of being alone or without their partner causes a great degree of anxiety. These individuals tend to fear abandonment in all relationships, but in romantic relationships especially.
These folks tend to have dependent or enmeshed in relationships. They tend to seek approval and support from others and need a high degree of responsiveness to feel supported.
They see their partner as the cure for their anxiety, and if they do not get the reassurance they need, they are likely to become more demanding and more clingy.