Biological Approach Psychology

The biological approach to psychology was developed from the study of biology and Charles Darwin’s research into evolution.

Darwin theorised that a species changes over time (evolves) to better fit its environment. They did this through a process he called natural selection. Occasionally, an animal is born with a variation that sets it apart from other members of its species, called a mutation (Darwin, 1859). If this mutation enables the animal to better survive in its environment than other members of the species, it is more likely to reproduce, passing down their mutation to their offspring. Over a long period of time, as animals that lack the mutation are killed off and those who have it reproduce, the entire species changes until all members

of the species in a particular area share this variation. Despite Darwin’s theory being considered flawed by scientists today, it contributed greatly to the development of the biological approach.
Due to advances in the study of biology, scientists were able to determine certain functions of the brain. This progress inspired William James (1842-1910) to write ‘The principles of psychology’, where he insisted that the study of the brain should be an important aspect of psychology (James, 1890). Recent development in medical technology has also allowed psychologists to more readily examine the brain in relation to behaviour.
The biological approach believes that all mental illness is based on the sufferer’s biology.

One key feature of the approach is that brain structure influences a person’s psychological state. The nervous system (composed of approximately 12 billion neurons) is the structure that controls all human behaviour and thought, so damage to this system can result in dramatic changes. This can be seen in the case of Phineas Gage, who was described as no longer being himself after miraculously surviving an accident in 1848 that put a tamping iron through his skull and frontal lobe (Harlow, 1848). A predisposition to particular mental illness can be passed on genetically, through inheriting defects in brain structure. Chemical imbalances can also cause mental illness such as depression resulting from low levels of serotonin.

There are many applications of the biological approach. One of them would be the use of chemotherapy, where the patient is given medication to correct or counter the chemical imbalance in their brain, such as Prozac (Fluoxetine) for sufferers of depression or Benzodiazepine for

anxiety.
One strength of the biological approach is that it is scientifically valid due to it’s focus on observable phenomenon.

Another is that it has clear proof that brain damage can cause cognitive difficulties in the form of case studies. A weakness of this approach is that it for the most part ignores environmental causes of mental illness (a person could be suffering from depression because of recent events in their life) and that there are some cases that they cannot explain, such as “the man with no brain” (Feuillet, Defour, and Pelletier, 2007) being capable of functioning.

The cognitive approach to psychology was established in the 1950 in response to the behaviourist approach. It criticised the approach for only focussing on the observable behaviour in response to outside stimuli, believing that the role of mental constructs was being ignored. The cognitive approach stresses that psychologists must place focus on both the mind and environmental factors, along with the relationship between the

two.
The cognitive approach is said to have officially begun in 1967 with Ulric Neisser’s Cognitive Psychology, which compares human thought to a computer (Neisser, 1967), an analogy that was then used by many cognitive psychologists. The human brain is like a computer in the way it manipulates and stores information. Information in the form of sensory stimulus is inputted (light reaches the retina), put through mediational processes (the electronic signal is interpreted inside the brain into what is understood as sight) before the appropriate output is created (people respond to what they see). Mediational processes include perception, language and memory.
Although all humans share the same mental processes, their response to stimuli can vary for each individual on account of their understanding of the world. Piaget (1952) claims that people develop their understanding of the world as children through a collection of schemata, mental representations of what we know about a stimulus. They organise new experiences based on how they are categorised (they see a dog and learn that dogs are small furry creatures with four legs). Schema can be modified through Adaption as the child increases its understanding of the things around it (they see another dog and learn that dogs can also be large). Piaget said that Adaption is based on two processes, Assimilation (the child generalises its existing knowledge to everything it encounters, all furry creatures with four legs are dogs) and Accommodation (schema are restructured to discriminate between similar but differing stimuli, dogs are furry creatures with four legs, but not vice versa, some are cats).
Piaget identified four stages of cognitive development, sensory-motor (0-2 years), where the child has no concept of object permanence (things still existing when unobserved), pre-operational (2-7 years) where object permanence develops but conservation (of numbers/volume) is difficult, concrete-operational (7-11 years) where conservation is learned and abstract thinking becomes possible if put in concrete terms, and the formal operational (11-13 years) where abstract thought and reasoning can be applied hypothetically.
One application of this approach is Cognitive Behavioural Therapy, which challenges the negative thoughts and behaviours that may lead to mental health problems (like depression).
Strengths of the cognitive approach include that it can be combined with other approaches, such as the behaviourist approach, which greatly increases its effectiveness, and that it attempts to be scientific, providing empirical evidence to back up its theories. Weaknesses of this approach include that it ignores the role of biological factors such as hormones in influencing behaviour, and that its focus on hypothetical constructs that cannot be physically observed makes its theories difficult to test.
This essay has attempted to explain and evaluate the four main approaches to psychology.