Biological Approach: Key Terms Glossary

Travis DixonBiological Psychology

The biological approach is about the study of behaviour by examining biological factors. The following glossary will help you know what those factors are.

Knowing the meaning of key terms is one of the first steps in learning (and revising) any topic in Psychology. The following is a list of key terms and their definitions for the Biological Approach in IB Psychology.

You can download a quiz to test your knowledge of these terms HERE.


  • The biological approach to understanding human behavior: Trying to understand human cognition and behaviour by looking at how they’re affected by biological factors.
  • Technological techniques (used to study the brain): A range of new technological techniques used to study the relationships between the brain and behavior, e.g. fMRI / MRI / PET / EEG (You should be able to summarize how at least one of these work, e.g. fMRI is a brain imaging technique that uses magnetic fields to measure brain activity. 
  • Localization (of brain function): The term used to describe how different parts of the brain perform different functions.
  • Neuroplasticity: The brain’s ability to change as a result of experience.
  • Neurotransmitter: A chemical messenger that sends messages along neural pathways. A variety of these have been identified and associated with different behaviours.
  • Neurotransmission: The process of neurons sending signals to each other – they send signals and communicate with one another through neurotransmitters.
  • Hormone: A chemical messenger that is transported through the bloodstream. These messengers affect physiological processes and behaviour.
  • Pheromone: A chemical messenger that is sent from one animal and it has an effect on a different animal.
  • Gene: A sequence of DNA. They have an effect on behaviour through gene expression – the sending of signals from the gene to outside the cell.
  • Genetic similarities: The use of people with similar genes in research, e.g. identical (monozygotic) and fraternal (dizygotic) twins. These are used as variables in studies on the relative effect of genes on behaviour (e.g. heritability).
  • Twin study: A twin study uses MZ and DZ twins and compares their behaviour in order to measure heritability.
  • Evolutionary explanation of behavior: Explaining how a behaviour helps an individual to pass on their genes by helping them to survive, procreate and/or produce healthy offspring (children).
  • Animal model (HL): The use of animals in research to understand how biological factors affect behaviour. (The term can refer to the specific animals themselves, but can also refer to the general explanation of biology and behaviour that is gained from the animal experiment/s.)

Remember that these aren’t the only terms you’ll need to know if you want to score top marks. You’ll need to be able to give specific examples for some of these topics and define them as well. But knowing these terms is the first step.

“Additional Terms”

  • Neural network: A series of connected neurons that allows the processing and transmitting of information. Specific networks are responsible for specific tasks.
  • Neural pruning: (aka Synaptic pruning) This happens when we lose these synaptic connections in a neural network because we do not use them.
  • Synapse: The space between two neurons where neurotransmitters are fired.
  • Excitatory neurotransmitter: An excitatory neurotransmitter binds to receptor sites and increases the chances of the post-synaptic neuron firing (sending a signal).
  • Inhibitory neurotransmitter: A neurotransmitter that binds to receptor sites and reduces the chances of the post-synaptic neuron firing (sending a signal).
  • Agonist: A chemical that amplifies the effect of a neurotransmitter by binding to the receptor sites of that neurotransmitter and activating them.
  • Antagonist: A chemical that reduces the effect of a neurotransmitter by binding to and blocking the receptor sites of that neurotransmitter.
  • Neuron: A neuron is a type of cell that receives, processes, and transmits information through electrical and chemical signals.