There are multiple theories about how<unk> s develop and likely occur due to a combination of environmental and genetic factors. The degree to whether environment or genetic influences have a more significant role varies by condition, with social anxiety disorder and agoraphobia having around a 50% heritability rate. Environmental Rachman proposed three pathways for the development of<unk> s: direct or classical conditioning (exposure to<unk>  stimulus), vicarious acquisition (seeing others experience<unk>  stimulus), and informational/instructional acquisition (learning about<unk>  stimulus from others). Classical conditioning Much of the progress in understanding the acquisition of fear responses in<unk> s can be attributed to classical conditioning (Pavlovian model). When an aversive stimulus and a neutral one are paired together, for instance, when an electric shock is given in a specific room, the subject can start to fear not only the shock but the room as well. In behavioral terms, the room is a conditioned stimulus (CS). When paired with an aversive unconditioned stimulus (UCS) (the shock), it creates a conditioned response (CR) (fear for the room) (CS+UCS=CR). For example, in case of the fear of heights (acrophobia), the CS is heights. Such as a balcony on the top floors of a high rise building. The UCS can originate from an aversive or traumatizing event in the person's life, such as almost falling from a great height. The original fear of nearly falling is associated with being high, leading to a fear of heights. In other words, the CS (heights) associated with the aversive UCS (almost falling) leads to the CR (fear). Though historically influential in the theory of fear acquisition, this direct conditioning model is not the only proposed way to acquire a<unk> . This theory in fact has limitations as not everyone that has experienced a traumatic event develops a<unk>  and vice versa. Vicarious conditioning Vicarious fear acquisition is learning to fear something, not by a subject's own experience of fear, but by watching others, often times a parent (observational learning). For instance, when a child sees a parent reacting fearfully to an animal, the child can also become afraid of the animal. Through observational learning, humans can learn to fear potentially dangerous objects—a reaction observed in other primates. A study on non-human primates, showed that the primates learned to fear snakes at a fast rate after watching parents' fearful reactions. An increase in fearful behaviours was observed as the non-human primates observed their parents' fearful reactions. Although observational learning has proven effective in creating reactions of fear and<unk> s, it has also been shown that by physically experiencing an event, increases the chance of fearful and<unk>  behaviours. In some cases, physically experiencing an event may increase the fear and<unk>  more than observing a fearful reaction of another human or non-human primate. Informational/Instructional acquisition Informational/instructional fear acquisition is learning to fear something by getting information. For instance, fearing electrical wire after hearing that touching it causes an electric shock. A conditioned fear response to an object or situation is not always a<unk> . There must also be symptoms of impairment and avoidance. Impairment is defined as an inability to complete routine tasks, whether occupational, academic, or social. For example an occupational impairment can result from acrophobia, from not taking a job solely because of its location on the top floor of a building, or socially not participating in a event at a theme park. The avoidance aspect is defined as behaviour that results in the omission of an aversive event that would otherwise occur, intending to prevent anxiety. Genetic With the completion of the Human Genome Project in 2003, much research has been completed looking at specific genes that may cause or contribute to medical conditions. Candidate genes were the focus of most of these studies until the past decade, when the cost and ability to perform genome-wide analyses became more available. The GLRB gene was identified as a possible target for agoraphobia. An area still in development is reviewing epigenetic components or the interaction of the environment on genes through methylation. A number of genes are being examined through this epigenetic lens which may be linked with social anxiety disorder, including MAOA, CRHR1, and OXTR. Each<unk>  related disorder has some degree of genetic susceptibility. Those with specific<unk> s are more likely to have first degree relatives with the same specific<unk> . Similarly, social anxiety disorder is found two to six times more frequently in those with first degree relatives that have it versus those that do not. Agoraphobia is believed to have the strongest genetic association.
Phobia
Claustrophobia
Alexithymia
Hyperreligiosity
Emotional lability
Mindfulness
Body integrity dysphoria
Automatism 