Biological factors: Research suggests that genetics and neurological differences, such as overactivity in certain parts of the brain, play a role in the development of anxiety disorders.Learned behavior: Early childhood experiences and environmental factors, such as having overprotective parents, may cause someone to develop certain patterns of anxious thinking. Anxious parents may also model their behavior to their children, who pick up on their habits.Negative thinking: Many people with anxiety disorders and other mental health conditions have fallen into patterns of repetitive negative thinking about themselves, others, and the world around them. Personality traits: People with certain personality traits, such as introversion (focusing on their inner life rather than external interactions) and perfectionism, are more likely to experience anxiety., Stress and anxiety that occur frequently or seem out of proportion to the stressor could be signs of an underlying condition, including: Generalized anxiety disorder (GAD) ., Anxiety, on the other hand, is defined by persistent, excessive worries that don’t go away even in the absence of a stressor. Anxiety leads to a nearly identical set of symptoms as stress: insomnia, difficulty concentrating, fatigue, muscle tension, and irritability. Both mild stress and mild anxiety respond well to similar coping mechanisms..