Abnormal behavior models: biological models

Abnormal behavior models: biological models

The biological models They argue that diseases are caused by biochemical or genetic abnormalities. From our perspective, they are necessary conditions, but not quite sufficient for the explanation of human behavior.

Further, it ignores the psychological explanations, or these occupy a very secondary place in the explanation, as well as environmental and contextual variables.

Nevertheless, psychology is, first and foremost, a biopsychosocial science, so you should not disregard biological influences on behavior. Therefore, below we will see some of the most important characteristics of the biological modelsin mental health.

Characteristics of biological models

  • The diagnosis will depend mainly on the information given by the patient, notwithstanding the corresponding physical examination.
  • Dismiss the influence of environmental variables (vital events, context, culture, social group) and psychological (cognitions, emotions, affections, behaviors)
  • It does not take into account the coping mechanisms of the person, his character, his will to live and overcome stressful situations.
  • It does not work in therapeutic adhesion, since this is influenced by psychosocial variables. For example, the patient's motivation for change and to move forward despite procedures that, in the short term, may be an inconvenience or restriction of his freedom.
  • Ignore the doctor-patient relationship, which greatly influences the course and prognosis of the disease. In psychology the therapist-patient relationship is fundamental, as indicated in the phenomenon of transfer.
  • This perspective gives you a Capital importance to medications, medical-surgical technologies, clinical analysis results and, in general, to medical and laboratory procedures.
    • Obviously, these issues are extremely important and should not be neglected, but the ideal would be a balance between the above and the cultivation of the doctor-patient relationship, paying attention to emotions, fears, expectations, desires, patient motivations, etc.

Genetic models as a fundamental part of biological models

Our behavior is polygeneticThere are several people responsible for the behavior, their contribution will result in the behavior.

Around this idea, the quantitative genetics, which is responsible for synthesizing the effects caused by many genes. On the other hand, we have the behavioral geneticists, who are looking for the genetic leaders of the behavior. To find those responsible, two types of studies are carried out.

  • Family background: A person with an alteration is studied and it is investigated if any family member has it too. When two generations appear with the same disease it is said that there is a high genetic component in the disease.
  • Twin studies: There are two kinds
    • Monozygotic: An egg fertilized by a sperm that in development is divided.
    • Dizygotic: Two ovules fertilized by two sperm.

Monozygotic twins have the same genes, the same genetic code. The Dizygotes do not have the same genetic code. These studies have to be complemented with others because the environment influences them.

This is why they are done data studies with twins given for adoption, which share the same genetic code but not the same environment.

Studies with twins given for adoption

The most frequent studies are the following:

  1. Child tracking: Parents with psychological disorders are looking for their children to find out if they, who were given for adoption, also have the disorders
  2. Parent Tracking: Find the parents of someone who was given up for adoption and find out if their parents have the disease
  3. Cross Parenting: Compare the children given for adoption in normal families and with disorders

The relationship between genetics and environment

There is a close relationship between genetics and environment. This has led to the creation of a series of models, called “Diathesis-stress models”.

These models say that people inherit the tendency to express a trait or behavior (these genes can be activated under stress conditions), that we have an inherited vulnerability to disorders, and that these are manifested will depend on the vital events of our life.

Stress factors are not universal. Not everyone stresses the same fact, nor in the same way. Many events can be positive and stressful at the same time. That depends on the person.

Inherited trend refers to diathesis or vulnerability. The drugs can cause some disease even while in small diathesis levels. Ex: Hallucinations.

A particular life event is the one that could produce a disorder, this event is referred to as "stressor" Having a high probability of depression, for example, means having a higher level of stress. You can have little diathesis and end up developing a psychosis, for example, taking drugs.

There is a variable that can alter this, the protection factors: external elements that can ensure that even if there is vulnerability or stress, a disease does not develop.


  • Peña-Herrera, B. (2018) General Psychopathology. Samborondón: Espiritu Santo University - Ecuador