We have all experienced this feeling of anguish, caused by the presence of a real or imaginary danger. It’s about fear.

But… what happens when this fear becomes pathological? Then we’re talking about a phobia. Eysenck’s theory of incubation arises to explain the acquisition of phobias.

What are phobias?

A phobia is an intense and persistent, almost immediate and unchanging fear or anxiety about a specific and objectively harmless object or situation, which is avoided or endured at the cost of intense discomfort, fear or anxiety .

A high percentage of the general population suffers from some kind of phobia. Among them, there are several types (social phobia, separation anxiety,…). More specifically and according to the DSM-5 (Diagnostic and statistical manual of mental disorders), within the specific phobia, there are different specifications according to the feared stimulus:

  • Animal.
  • Specific situation.
  • Natural environment.
  • Blood-injection-damage.
  • Situational.
  • Others.

The most common phobia in the non-clinical population is the specific phobia. In the clinical population, however, the most common phobia is the panic disorder with agoraphobia. This type is the most severe and disabling of all types of phobias.

Acquisition of phobias

To understand what Eysenck’s Incubation Theory is like, it is important to understand some ideas about the acquisition of phobias . Generally, phobias are acquired by direct conditioning, although they can also be acquired indirectly, that is, by vicarious and semantic conditioning (when there are information relationships between stimuli).

As we have seen, most phobias are acquired by direct conditioning, although there are differences in the type of phobia:

Agoraphobia and claustrophobia

These two types of phobias are most often acquired through past traumatic experiences .

Blood phobia

It is mainly acquired by vicarious conditioning . Here the transmission of information plays a very important role.

Animal phobia

These are the phobias most associated with indirect conditioning (vicarious conditioning in accordance with the “disease avoidance” model proposal, according to which sensitivity to repugnance/contamination is transmitted to small animals).

Eysenck’s theory of incubation

Eysenck’s theory of incubation is considered the “third great model of conditioning”. It arises as a complement to the law of extinction and is a model based on classical conditioning.

This theory explains why extinction does not occur in phobias, as well as the process of resistance to extinction. In turn, it considers two types of conditioning:

Type A conditioning:

Motivation is manipulated externally , and unconditioned response (IR) and conditioned response (CR) are different. For example, in salivation conditioning, the IR would be food intake, and the CR would be salivation.

Type B conditioning:

Here motivation is generated by the conditioning paradigm itself, and depends less on the motivational state of the organism . CR and IR are similar. For example, in the case of aversive conditioning.

According to this theory, anxiety is acquired and maintained by type B conditioning.

The theory defends that exposure to the conditioned stimulus (CS) (without the presence of the unconditioned stimulus, IE) does not cause the extinction of CR. Thus, CR acts as a reinforcer because of its similarity to IR.

For the phobia to be acquired, the strength of CR must be high (intense), and the duration of exposure to EC must be short.

The Napalkov Effect

Following Eysenck’s theory of incubation , the Napalkov Effect is proposed. This is an experimental demonstration that there can be a paradoxical increase (incubation) in an autonomous response (e.g. blood pressure) to the successive presentation of CD alone (in the extinction phase).

Alternatives to the Eysenck model

Some alternatives to Eysenck’s incubation theory have been proposed. One of them is the restoration of the fear proposed by Rescorla .

According to this, a mnestic representation of the EC-EI association is produced, and in view of the exposure of the EC, the representation of the EI is activated.

Another alternative is the re-evaluation of the EI proposed by Davey . According to this other author, anxiety is incubated if after each presentation of the CD, the subject reevaluates the EI and overestimates it. The tendency to perform this over-evaluation will depend on:

  • The willingness to process the aversive aspects of an event.
  • The tendency to discriminate and overestimate the intensity of one’s anxiety reactions.

Bibliographic references:

  • Belloch, A.; Sandín, B. and Ramos, F. (2010). Manual of Psychopathology. Volume II. Madrid: McGraw-Hill.
  • American Psychiatric Association (2013). DSM-5. Diagnostic and statistical manual of mental disorders (5th Edition). Washington, DC: Author.
  • Tortella, M. (2014). Los Trastornos de Ansiedad en el DSM-5, 110. Medicina psicosomática y psiquiatría, revista iberoamericana de psicosomática.