Outline principles that define the Biological Level of Analysis


  • State what you are doing in the essay 
    • This essay will give a brief summary of the principles that define the biological level of analysis. 
  • Define the biological level of analysis 
    • The biological level of analysis (BLA) states that all cognitions, emotions and behaviours have a physiological basis. 
  • State the principles of the BLA 
    • There are three underlying principles that define the BLA 
      1. Emotions and behaviours are products of the anatomy and physiology of the nervous and endocrine systems 
      2. Animal research may inform our understanding of human behaviour 
      3. Patterns of behaviour can be inherited; behaviour is innate because it is genetically based 
  • Purpose of the Principles 
    • These principles are the main ideas that have driven focused research on specific areas of behaviour and physiology
    • They also allow us to understanding how behaviour can be caused or influenced by biological factors 
  • The BLA assumes that behaviour is a result of biological/physiological factors 
    • Links with the principle that there are biological correlates of behaviour. 
  • Bidirectional relationship between other levels of analysis 
    • Behaviour is not only a result of biological factors alone; other factors like cognitions and the environment interact with one another, resulting in specific behaviours
    • Cognition can affect biology and biology can affect cognition
    • The environment can also affect physiological processes and vice versa 
  • Nature vs. nurture debate 
    • Debate between whether human behaviour is attributed to biological or environmental factors
    • Psychologists have an interactionist approach and take both into account 
  • Reductionist approach 
    • At the BLA, researchers break down complex human physiology and behaviour into its smallest components to study 
  • Outline Essay
    • Two of the three principles will be outlined in the following essay.


The first principle states that
1. Cognitions, emotions and behaviours are products of the anatomy and physiology of our nervous and endocrine systems. There are biological correlates of behaviour

Describe the principle

  • Specific brain processes, neurotransmitters, and hormones can play a role in behaviour. 
  • These physiological processes are what forms the basis of the biological level of analysis, in relation to how it functions and therefore affects human behaviour in everyday life. 
    • For example, this relates to the idea of localization of function, in that each area of the brain is responsible for coordinating a certain part of our body/nervous system and thus our behaviour. 

Outline the approaches that can be made towards this principle 

  • This can be viewed using a reductionist approach, i.e. breaking down complex behaviour into smaller parts for analysis. 
  • Or a deterministic approach can be used, which suggests that human behaviour is completely physiological and that we are not capable of “free will,? but by predictable bodily functions, which is also assumes a correlational approach. 

Supporting Study 1: Adrian Raine (1997)

Introduce Study/Signpost 

  • A study which supports this principle was conducted by Adrian Raine (1997), in which he aimed to determine whether criminals pleading Not Guilty under Reason of Insanity (NGRI) had any biological defects, which explained their distinct behaviour. 
Connection of study to principle 

  • Raine showed that there was a difference in brain structure between normal subjects and NGRI’s. He found that: 
    • NGRIs had less activity in prefrontal cortex which is linked to self-control and emotion 
    • Subsequently showing how biological factors (brain structure) may thus affect behaviour 
  • This study supports the idea that there are biological correlates of behaviour because it was shown that there was a correlation between the behaviour of aggression and the physiology of the brain, in how when parts of the brain are damaged, the functions that are associated with it are impaired. 

The next principle that will be outlined of the BLA is that 

  • Animal research can provide insight into human behaviour
Describe the principle 

  • This principle is based on Charles Darwin’s theory of evolution. 
    • Revolves around the idea that humans and many animals are different species now because of thousands of years of evolutionary adaptation to environmental demands.
    • Natural selection - those who adapt best to environmental challenges will have characteristics better suited to the environment and are more likely to pass on these traits 
  • Evolution is attributed as to why humans and some animals share some similar anatomy and behaviour 
    • Therefore, inferences about humans can be made from animal research. 
  • Many animals, especially monkeys of the ape family have similar bodily systems as ours, so it can be presumed that when put in the same situation; humans would behave similarly to the animals. 
  • This idea is useful when testing treatments, although it does raise ethical issues in the treatment of animals, unless it is for a good cause and that it can be applied to humans and their health.

Supporting Study 2: Berthold (1849)

Introduce Study/Signpost

  • An example of a study that used animals as a substitute for humans because of ethical concerns is by Berthold (1849). 
Connection of study to principle 

  • Berthold observed that roosters were less masculine and did not crow or participate in sexual or aggressive behaviour after its testes were removed 
  • This thus shows that the hormone secreted by the testicles (testosterone) is linked with dominant male behaviours. 
  • Berthold’s study demonstrates the principle of the BLA because inferences were made to humans from roosters about the effect of testosterone on behaviour to inform our understanding of aggression. 
  • It also highlights the importance of using animals to determine human behaviour. 


  • Summarize the significance of studies in supporting the three principles (*do not restate the principles and studies mentioned as this wastes time and are repetitive).
    • It can be seen that there is sufficient support for the principles of the BLA.
    • It can be seen that in all three principles, other factors need to be taken into account before determining these principles as the sole influences of human behaviour.
    • These principles help to guide studies from a biological perspective.
    • Views from all levels of analysis need to be taken into account before reaching a determined decision on influences on human behaviour.