Final answer:
Attachment anxiety is associated with the personality trait of neuroticism, a dimension of the Big Five personality traits where individuals tend to experience negative emotions like anxiety more frequently.
Step-by-step explanation:
Attachment anxiety is most closely associated with the personality trait of neuroticism. Neuroticism is one of the Big Five personality traits and is characterized by a tendency to experience negative emotions, such as anxiety and depression. People with higher levels of neuroticism are more likely to have an overactive sympathetic nervous system, causing them to frequently experience a fight-or-flight reaction, even in low-stress situations, and are thus more prone to attachment anxiety. On the other hand, people high on stability (opposite of neuroticism) require more stimulation to trigger this reaction and are generally more emotionally stable.