"For the anxious attachment style, intimacy and closeness are the core needs. These needs results in wanting reassurance that things are okay, and that their partner is readily accessible to them emotionally and maybe even physically depending on the situation. These needs are neither good nor bad, they are simply needs.
The anxious style has a “spidey sense” for very small shifts in the relationship. In fact, science has shown us that they pick up on changes in emotions and facial cues faster than any other attachment style. While this style is very perceptive, they also have a tendency to jump to conclusions or catastrophize situations if they do not have their spidey sense under control. For example, they may take a situation where their partner isn’t returning their text messages, which is an uncharacteristic behaviour, and jump to conclusions that there is something wrong, their partner is mad, is with someone else…etc.
When the anxious attachment style feels that something is not right in their relationship their attachment system activates. The attachment system is a mechanism in the brain that is responsible for monitoring and tracking the safety and availability of our attachment figures. Even the slightest hint that something is wrong will trigger the anxious person’s attachment system. This triggering highjacks the brain and reestablishing connection to their partner becomes the main priority. Once their attachment system is activated, they cannot calm down until they have clear indication from their partner that s/he is truly there and the relationship is safe. Once their partner responds in a way that reestablishes security, they revert back to their calm, normal self.
When attachment needs go unmet, the behaviour escalates and the anxious person may resort to protest behaviour. A protest behaviour is any action that tries to reestablish connection with the partner and get their attention. If we can reassure our partner’s needs before they engage in protest behaviour, then they can be calmed very quickly. If things continue to escalate and needs continue to go unmet, protest behaviour ensues and can harm the relationship."
It also appears that I almost always choose avoidant types, which is a complete trainwreck for my attachment style. Needless to say, it's kind of incredible how much all of this explains.
Source.