Psychology is one of the many true mysteries of the sciences of today. The fundamental question it tries to answer is about the mind and soul (psyche) relation with our physical bodies. Are the body and mind separate? Or are they the same? Each psychological approach proposes a different answer to this philosophical question, known as the mind-body problem.
In this article, we're going to look at how psychology uses knowledge and methods of biology in a biological approach to answering the fundamental questions of what determines individuals' behaviour and thinking.
- First, we will give a biological approach definition.
- After, we look at some biological approach assumptions.
- Then we will explore some biological approach examples.
- Next, we will briefly look into the biological approach to depression.
- Finally, we will examine the biological approach evaluation, including biological approach strengths and weaknesses.
Biological Approach Definition
The biological perspective proposes that biological structures determine our behaviour and thoughts. These structures include neurons, brain regions, neurotransmitters or genes. A simple definition of this is:
A biological approach in psychology involves studying human biology to understand human behaviour.
In contrast to the cognitive approach, in the biological approach, the mind is not seen as separate from the physical makeup of our bodies. There is no 'ghost in the machine; instead, the physical machine is made up of many structures, e.g. cells that work together to enable us to function.
Biopsychology is where psychology and biology overlap. The essential ideas taken from biology and applied to psychology are natural selection, localisation of brain functions, and brain chemicals as a basis of behaviour. Let's have a closer look at how these ideas impact behaviour.
Biological Approach Assumptions
In biopsychology, exploring human biology and genes throughout history and today using more advanced technology has created some assumptions that the biological approach follows. There are three main ones:
- Genes determine our behaviour.
- Brain functions are localised.
- Neurochemicals are the basis of behaviour.
One of the key assumptions of the biological approach is that traits and behaviours can be inherited from our parents. It also assumes the traits get passed down from one generation to another to ensure survival in the natural environment.
Fig 1. - Biological approaches propose that genetics and biology determine thoughts and behaviour.
To highlight how genetics and biology can influence our actions, we will look at some examples of the biological approach that aims to explain human behaviour.
Biological Approach Examples
Here we will look into some examples of biological approaches, including genes determining behaviour, evolutionary explanations of behaviour, brain functionality, and neurochemicals and behaviour.
Biological Approach: Genes Determine Behaviour
Natural selection is the idea that biological advantages of a species (e.g., sharper beaks, bigger brains, better night vision) get passed down to future generations in an inherited biological trait and was proposed by Darwin in what is commonly known as the theory of evolution.
Good to know: In contrast to everyday language, in science, a theory is an overarching idea that has been overwhelmingly confirmed by evidence. This is as close as science gets to calling something a fact. An idea that you speculate about, however, is called a hypothesis.
A century after Darwin, advances in biotechnology have allowed us to confirm the existence of inherited physical traits, or genes, in cell DNA. Geneticists are still trying to figure out how genes influence behaviour; however, twin studies and family histories show that a lot of behaviour can be explained using the ideas of genotypes and phenotypes.
We carry a specific combination of our parents' genetic information (DNA) called the genotype. However, only the dominant traits are observable. These outwardly observable genes are called phenotypes, determined by both the genotype and the environment.
Some examples of phenotypes are hair colour, height, eye colour and even behaviour.
Knowing about genotypes and phenotypes has helped us understand why some people show certain behaviours, and some don't.
Some mental illnesses, such as schizophrenia, are thought to have a genetic component as they are often found passed on in family lines but not always.
Biological Approach: Evolutionary Explanations of Behaviour
Evolutionary adaptation means the traits passed down over many generations best help the individual survive in the natural environment.
Most adaptations of the theory of evolution address physical traits. But psychology is particularly interested in behavioural traits, meaning how people have developed over time to better adapt to their environment. This includes behaviours such as altruism, attachment and communication through facial expressions.
Attention bias; experiments have shown that even babies tend to pay more attention to spiders and snakes than to cars. In reality, both can be equally deadly. Why could this be a useful trait in nature?
One possible explanation for this is that, over generations, those who paid attention to and consequently learned to fear spiders and snakes survived longer and had a chance to procreate more than those who died of snake- or spider bites. This would mean that the ability to learn to fear snakes and spiders is an adaptation that evolved in humans due to the environment.
Biological Approach: Brain Functionality
Biopsychology assumes that different parts of the brain have different functions rather than the whole brain working at all times.
There are many methods for studying brain anatomy, including imaging like fMRI, PET scans, post mortems, or studying the behaviour of people with pre-existing brain damage.
Research has revealed that different areas of the brain correlate with specific functions.
One of the ways that brain localisation can be proved is through transcranial magnetic stimulation (TMS), which temporarily blocks the electrical activity of specific brain regions.
Depending on which specific brain areas are targeted, people lose speech or control of their hands for a minute or two (no permanent damage occurs). This demonstrates that specific brain regions control the brain's normal use.
Biological Approach: Neurochemicals and Behaviour
A lot of behaviour can be explained by the presence or absence of specific messenger chemicals in the brain- specifically neurotransmitters, hormones and immune system messengers.
The biological approach explains that excess dopamine levels in specific brain regions cause the positive symptoms of schizophrenia. And that lower dopamine levels in other regions contribute to the negative symptoms of schizophrenia.
Evidence of the role of neurochemicals in mental illnesses is that antipsychotics that target the abundance of neurotransmitters re-absorbed and available in the synapse have shown to be an effective treatment for reducing positive and negative symptoms of schizophrenia.
Biological Approach to Depression
Another example of a biological approach to explaining psychological theories involves the aetiology (the cause of) and treatment of depression, involving neurochemicals that influence mood and behaviour.
Research links depression to a deficit of serotonin and dopamine neurotransmitters.
The biological model would treat major depression by using drug therapy, involving prescribing and taking drugs (known as antidepressants) to correct the imbalance of neurotransmitters.
Another practical application of advances in biopsychology is transcranial direct current stimulation (TDCS), a kind of low-voltage electrical current applied to the brain, which holds promise in alleviating symptoms of depression.
However, this approach does not consider the emotions and environmental stressors that can play a part in the development and continuation of the illness, which we will discuss more in an evaluation of the biological approach.
Fig 2. - A biological treatment for depression involves antidepressant drugs that balance neurotransmitter levels.
Biological Approach Strengths and Weaknesses
The biological perspective has several advantages over other approaches but also some disadvantages. Let's break down its evaluation.
Biological Approach Strengths
First, multiple strengths of the biological approach exist, making this approach reliable and objective compared to some other approaches. Let's have a look at some of its pros:
- Objective scientific and biological evidence can be found using technology. Continually building on scientific evidence increases this research field's reliability and validity.
For instance, electroencephalographs (EEGs, which analyse sleep/wake cycles), Functional Magnetic Resonance Imaging (fMRI) machines to highlight areas of the brain being used during specific actions and, as mentioned previously, drug therapy and genetic analysis in twin studies.
- Real-world applications of these biological discoveries help to improve people's lives greatly. As we have mentioned with drug therapy treatments, other examples include drugs (e.g. L-Dopa) that increase dopamine levels for people with Parkinson's Disease to reduce shaking and muscle spasm symptoms.
Biological Approach Weaknesses
Although there are many advantages to the biological approach, it's not perfect. Let's take a look at some of the weaknesses of this approach:
- The approach oversimplifies humans and our physiology. Other factors may influence our behaviour, and one biological treatment may not help those affected by external issues.
- Determinism relating to the biological approach is the concept of thinking if people's behaviour is determined by their genetics and biology, then can they truly control and be held accountable for this behaviour? This brings up philosophies about the human ability of free will and whether we are consciously responsible for our behaviour.
- It is said the biological approach doesn't consider individual differences within people. People may be biologically similar but not identical, so can it really be assumed that a biological treatment will work best for the majority? There can be differences in gender, ethnicity and neurodiversity that may mean biological approaches cannot be generalised to the whole population so easily.
- There are issues of correlation vs causation in scientific research. A correlation assumes that as one variable changes (e.g. neurotransmitter levels), the other variable changes (e.g. mood). The issue is that we can't establish which variable is the cause and which is the effect or understand if any mediational processes are influencing these findings.
Fig 3. - Factors relating to our environment may also influence human thought and behaviour.
Recently, health psychology has started applying an updated version of the biological approach to illnesses called the biopsychosocial model.
The model has more of a holistic view of psychological well-being and tries to address all the different social, psychological and biological factors that could influence people's thoughts and behaviour.
Biological Approach - Key takeaways
- The biological approach tries to explain the behaviour and thinking of individuals through biological structures.
- The core assumptions of the biological approach are that genes and neurochemicals determine behaviour. Another hypothesis is that brain functions are located in specific parts of the brain.
- The biological approach believes that depression is linked to a deficit of serotonin and dopamine neurotransmitters.
- The strengths of the biological approach are that there are many practical applications for biological research into the behaviour and that the methods used are scientifically sound.
- The weaknesses of the biological approach are that other possibly important variables aren't taken into account and that it's a correlative approach. It opens up questions in society and law regarding whether people can be held accountable if their biology determines behaviour.
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