The Biological Level of Analysis.

Welcome to the Biological level of analysis.

The biological level of analysis argues that there are physiological origins of many behaviours, and that human being should be studied as biological systems. This is not to say that behaviour is not the result of biological systems alone, but what we should also consider how the environment and cognition may interact with biological systems and affect physiology. This relationship is biderectional i.e. biology can affect cognition and cognition can affect biology.

Many physiological factors can play a role in behavior: brain processors, neurotransmitters, hormones and genes. However, physiology does now work on its own; it responds to environmental; stimuli such as stressful experience , an attractive person walking by, or something as extreme as brain damage caused by an accident. One of the major controversies in the history of psychology is the nature nurture debate, in which researchers debate whether human behaviour is the result of biological or environmental factors. . The interactionist approach used by modern psychologists does not adopt either the biological or environmental, but adopts a more holistic picture of human nature.

The biological level of analysis is based on certain principles about human behaviour. One of these principles is that behaviour can be innate because it is genetically based. If this principle is accepted it is logical to believe that evolution may play a key role in behaviour. Another principle is that animal research can provide an insight into human behaviour; as a result a significant amount of research is undertaken using animals. A third principle is that there are biological correlates of behaviour. The implication of this is that it should be possible to find a link between a specific biological factor (e.g. a hormone) and a specific behaviour, and this is the aim of researchers working at the biological level of analysis.

Biological researchers often take a reductionist approach to the study of human behaviour. This is a micro-level of research, which breaks down complex human behaviour into ints smallest parts-for example, focusing on the role of a gene a neurotransmitter, or a protien. This micro approach is sometimes criticized for being overly simplistic in explaining behaviour. However, it is important to understand how several factors may interact to cause certain behaviours.

The learning outcomes for this unit are outlined below. Please revisit and review as we progress through the unit.

  1. Outline principles that define the biological level of analysis.

  2. Explain how principles that define the biological level of analysis may be demonstrated in research (through theories and studies)

  3. Discuss how and why particular research methods are used at the biological level of analysis

  4. Discuss ethical considerations related to research studies at the biological level of analysis

  5. Examine one study to localization of function of the brain

  6. Explain using examples, the effects of neurotransmission on human behaviour.

  7. Explain using two examples, functions of two hormones on human behaviour.

  8. Discuss two effects of the environment on physiological processes

  9. Examine one interaction between cognition and physiology on behaviour

  10. Discuss the use of brain imaging technologies in investigating the relationship between biological factors and behaviour.

2.2 Biological level of analysis: genetics and behavior

  1. Discuss the extent to which genetics influence behaviour

  2. Explain one evolutionary explanation of behaviour

  3. Discuss ethical considerations in research into genetic influences on behaviour.

For each of unit we have designed a study guide to help you focus on the learning outcomes. This will prove to be a valuable resource when it comes to revising for tests and final examinations. You must complete the sections for each of the learning outcomes. Please pay particular attention to the command terms. The marking for the completion of your review is set out on the front page.

The following information is drawn from:

Law, Halkkiopoulos & Bryan-Zaykov (2010) Psychology for the IB Diploma. Pearson baccalaureate.

Crane (2010)IB Psychology Course Companion IBO Oxford

Hannibal (2012) IB psychology Study Guide. Oxford

Inthinking psychology resources for teachers.

Link to Inthinking

I would like to acknowledge the excellent resources they have provided in delivering the IB psychology course.

[Week beginning 8/9/14]

As part of understanding yourself and how you learn. Take a look at the following concepts of learning styles. Which learning style do you respond to? Ask yourself how we can build a learning environment that reaches out to all our learning styles. Please make suggestions on how we can improve the lessons.

Why Learning Styles? Understand the basis of learning styles

“Your learning styles have more influence than you may realize. Your preferred styles guide the way you learn. They also change the way you internally represent experiences, the way you recall information, and even the words you choose. We explore more of these features in this chapter.

Research shows us that each learning style uses different parts of the brain. By involving more of the brain during learning, we remember more of what we learn. Researchers using brain-imaging technologies have been able to find out the key areas of the brain responsible for each learning style.

For example:

  • Visual: The occipital lobes at the back of the brain manage the visual sense. Both the occipital and parietal lobes manage spatial orientation.
  • Aural: The temporal lobes handle aural content. The right temporal lobe is especially important for music.
  • Verbal: The temporal and frontal lobes, especially two specialized areas called Brocas and Wernickes areas (in the left hemisphere of these two lobes).
  • Physical: The cerebellum and the motor cortex (at the back of the frontal lobe) handle much of our physical movement.
  • Logical: The parietal lobes, especially the left side, drive our logical thinking.
  • Social: The frontal and temporal lobes handle much of our social activities. The limbic system (not shown apart from the hippocampus) also influences both the social and solitary styles. The limbic system has a lot to do with emotions, moods and aggression.
  • Solitary: The frontal and parietal lobes, and the limbic system, are also active with this style.”

2.1 Outline principles that define the biological level of analysis: Explain how these principles can be demontsrated in research.

The principles are the main ideas that have driven research to focus on specific areas of human behaviour and physiology in order to achieve an understanding of how behaviour can be caused by or influenced by biological factors. Throughout the unit you need to be looking at how these key principles apply.

There are three key principles that define the biological level of analysis:

(1) There are biological correlates of behaviour: for example; Emotions and behaviour are products of the anatomy and phsiology of the nervous and endocrine systems. This means that there are physiological origins of behaviour such as neurotransmitters, hormones, specialised brain areas, and genes. The biological level of analysis is based on reductionism, which is the attempt to explain complex behaviour in terms of simple causes. For example Newcomer at al (1999) performed an experiment on the role of the stress hormone cortisol on verbal declarative memory.

(2). Animal research can provide insight insight into human behaviour. This means that researchers use animals to study physiological processes, because it is assumed that biological processes in non-human animals are the same as in humans. One important reason for using animals is that there is a lot of research where humans cannot be used for ethical reasons. For example this can be demonstrated in Rosenweig and Bennet (1972) who performed a experiment to study the role of environmental factors on brain plasticity using rats as participants and Martinez and Kesner (1991) who carried out an experiment on the role of neurotransmitters in learning and memory.
(3) Human behaviour is, to some extent, genetically based. This means that behahviour can be explained by genetic inheritance, although this is rarely a full explanation since genetic inheritance should be seen as genetic predisposition which can be affected by environmental factors. Researchers interested in the genetic origin of behaviour often use twin studies so they can compare one twin with the other on a variable such as intelligence, depression or anorexia nervosa. this can be demonstrated by Bouchard et al (1990) who performed the Minnesota twin study, a longitudinal study investigating the relative role of genes in IQ.
Click to access powerpoint.

Biological research methods and ethics

Discuss how and why particular research methods are used at the biological level of analysis.

Discuss ethical considerations related to research studies at the biological level of analysis.

The biological level of analysis, according to the principles outlined above, tends to use three main research methods: We have investigated these in the previous unit on Research Methodology. At the back of your workbooks keep a diary of where these methods are used and to what effect.

Laboratory experiments; At the biological level of analysis these experiments are commonly used to establish cause and effect relationships between the variables studied. A key point at this level of analysis is the use of animal experiments as well as human experiments. When researchers want to test the effect of changes to physiology (ie by injection or hormones) or to test the effectiveness of a new medication (e.g. for schizophrenia, it is ethically unlikely to carry out the experiment.

Case Studies: The case study is another way to deal with the problem of carrying out research on human participants. Instead of causing some kind of change to a persons physiology, researchers can take advantage of naturally occurring irregularities (e.g. brain damage or long term drug use) by obtaining detailed information about the participants condition. As this approach is mostly descriptive, there is relatively little harm that can be done to participants. The most important ethical risk is the depth of information and the researchers steps to protect anonymity.

Correlation studies: As with the case study, the correlation study does not usually necessitate the manipulation of an independent variable that might cause damage to the participant : instead it takes scores on two or more measures and works out the relationship between them. this is often at the core of twin studies and adoption studies, which are important sources of information about the link between genetics and behaviour.

[Week beginning 15/9/14]

Physiology and behaviour: Localisation of function.

Examine one study related to localization of function in the brain.

The brain and behaviour. Over the past hundred years, few areas of psychology quite so rapidly as brain research. As technology as progressed, so has our ability to monitor and map the brains activity . The brain is seen as the command centre of human activity, and psychologists continue to develop a deeper understanding of its role and how it matures over a lifetime. In this section we look at the main way researchers have investigated brain function and evaluate these methods. We will be looking at four theories that support this; namely,

Case study, Phineas Gage. Case study,H.M. Roger Sperry split brain and Broca and Wernicke ‘asphasi’

Remember if you get this question in an examination you are required to refer to one study only.

First of all lets have a look at the case study of Phineas Gage.

We shall look at look at the secret history of the brain to look at the studies of Paul Broca and the case study of HM. You will be required to work in groups and set up the experiments by Brenda Milner (for HM) and the spit brain Sperry and Gazzinga. Enjoy!!!!!!! Remember to include the study by KIM and Hirsh to support Brocca and Wernicke.

Assessment. Next week you will be set a twenty minute period for a short answer response on this learning outcome. revise the case study you are most interested in and familiar with.

Well done with the essays we shall post them for safe keeping.

[Week beginning 23 September)

2.3 Explain using examples, the effects of neurotransmission on human behaviour.

This outcome asks us to explore the effects of neurotransmitters on behaviour. First of all we need to understand how neurons work. Out of the one hundred types of neurotransmitter we will be focusing on four: namely Acetylcholine; Dopamine; Serotonin and Norepinephrine; and then identifying key studies that support.

We will be following the powerpoint and accompanying videos.

Access the key powerpoint here.



Please click here to access “The Brain powerpoint”

The Brain powerpoint

Please click here to access information on neurons and neurotransmitters. Ref: www.simplypsychology.

Assessment:  Working in groups you will be required to produce a pictorial representation of the process of neurotransmision.  You will be given one of the four key types of neurotransmitter; i.e Acetylcholine; Dopamine; Norepinephrine and Serotonin, then identify the behaviour associated with them and introduce research study that supports.  You will be given direction to which studies should be applied.  You will then present your information to the rest of the class. 

Excellent presentations. Well done everyone.

We discussed localisation of brain function and how we might live without certain areas of the brain.   We also discussed brain plasticity and how the brain can develop new connections through dendritic branching.  This we will look at in more detail in learning outcome 2.5 “Discuss two effects of the environment on physiological processes.” but, for now lets look at the case study of Jody who is testament to the power and ability of the brain to mend itself.

[Week beginning 30 September]


2.4. Explain, using examples, functions of two hormones on human behavior.

The key information is on the neurotransmission powerpoint.  The key hormones that need to be identified are; Cortisol and memory; Oxytocin and trust; Melatonin and sleep.  Working in groups you will discuss, identify key studies and present to the rest of the class.  You can also find a you-tube clip that supports the studies.


Functions of hormones of human behaviour.


This week will be identifying different types of hormones and their  functions.  The learning outcome  is to explain,[see command term] using examples, functions of two hormones on brain behaviour.


You will be required in groups to make a presentation on one of the following topics that identify how hormones affect behavior.


  1. The chemistry of attachment
  2. Homeostatic regulation of sleep
  3. Seasonal affective disorder (SAD)
  4. How your brain responds to stress
  5. The fight or flight response.


Presentations are expected to be about 10 minutes in length, please concentrate on the functions of hormones. We shall try using binders this time.

Once you have completed your presentations chose one of the topics to write a short essay on the learning outcome. ‘Explain using examples, functions of two hormones on human behaviour’.


[Week beginning 13 October ]

2.5 Discuss two effects of the environment on physiological processes.

How the environment effects the brain,

One of the big questions of the biological level of analysis is, how much the environment impacts the brain? “The brain is a dynamic system that interacts with the environment.  In a sense, the brain is physically sculpted by experience. not only can the brain determine and change behaviour, but, behaviour and change can change the environment.

Brain Plasticity–An Overview

What is brain plasticity? Does it mean that our brains are made of plastic? Of course not. Plasticity, or neuroplasticity, is the lifelong ability of the brain to reorganize neural pathways based on new experiences. As we learn, we acquire new knowledge and skills through instruction or experience. In order to learn or memorize a fact or skill, there must be persistent functional changes in the brain that represent the new knowledge. The ability of the brain to change with learning is what is known as neuroplasticity.

To illustrate the concept of plasticity, imagine the film of a camera. Pretend that the film represents your brain. Now imagine using the camera to take a picture of a tree. When a picture is taken, the film is exposed to new information — that of the image of a tree. In order for the image to be retained, the film must react to the light and ?change? to record the image of the tree. Similarly, in order for new knowledge to be retained in memory, changes in the brain representing the new knowledge must occur.

To illustrate plasticity in another way, imagine making an impression of a coin in a lump of clay. In order for the impression of the coin to appear in the clay, changes must occur in the clay — the shape of the clay changes as the coin is pressed into the clay. Similarly, the neural circuitry in the brain must reorganize in response to experience or sensory stimulation.

Facts About Neuroplasticity

FACT 1: Neuroplasticity includes several different processes that take place throughout a lifetime.

Neuroplasticity does not consist of a single type of morphological change, but rather includes several different processes that occur throughout an individual?s lifetime. Many types of brain cells are involved in neuroplasticity, including neurons, glia, and vascular cells.

FACT 2: Neuroplasticity has a clear age-dependent determinant.

Although plasticity occurs over an individual?s lifetime, different types of plasticity dominate during certain periods of one?s life and are less prevalent during other periods.

FACT 3: Neuroplasticity occurs in the brain under two primary conditions:

1. During normal brain development when the immature brain first begins to process sensory information through adulthood (developmental plasticity and plasticity of learning and memory).

2. As an adaptive mechanism to compensate for lost function and/or to maximize remaining functions in the event of brain injury.

FACT 4: The environment plays a key role in influencing plasticity.

In addition to genetic factors, the brain is shaped by the characteristics of a person’s environment and by the actions of that same person.

Developmental Plasticity: Synaptic Pruning

Gopnick et al. (1999) describe neurons as growing telephone wires that communicate with one another. Following birth, the brain of a newborn is flooded with information from the baby?s sense organs.  This sensory information must somehow make it back to the brain where it can be processed. To do so, nerve cells must make connections with one another, transmitting the impulses to the brain. Continuing with the telephone wire analogy, like the basic telephone trunk lines strung between cities, the newborn?s genes instruct the “pathway” to the correct area of the brain from a particular nerve cell. For example, nerve cells in the retina of the eye send impulses to the primary visual area in the occipital lobe of the brain and not to the area of language production (Wernicke?s area) in the left posterior temporal lobe. The basic trunk lines have been established, but the specific connections from one house to another require additional signals.

Over the first few years of life, the brain grows rapidly. As each neuron matures, it sends out multiple branches (axons, which send information out, and dendrites, which take in information), increasing the number of synaptic contacts and laying the specific connections from house to house, or in the case of the brain, from neuron to neuron. At birth, each neuron in the cerebral cortex has approximately 2,500 synapses. By the time an infant is two or three years old, the number of synapses is approximately 15,000 synapses per neuron (Gopnick, et al., 1999). This amount is about twice that of the average adult brain. As we age, old connections are deleted through a process called synaptic pruning.

Synaptic pruning eliminates weaker synaptic contacts while stronger connections are kept and strengthened. Experience determines which connections will be strengthened and which will be pruned; connections that have been activated most frequently are preserved. Neurons must have a purpose to survive. Without a purpose, neurons die through a process called apoptosis in which neurons that do not receive or transmit information become damaged and die. Ineffective or weak connections are “pruned” in much the same way a gardener would prune a tree or bush, giving the plant the desired shape. It is plasticity that enables the process of developing and pruning connections, allowing the brain to adapt itself to its environment.

Plasticity of Learning and Memory

It was once believed that as we aged, the brain?s networks became fixed. In the past two decades, however, an enormous amount of research has revealed that the brain never stops changing and adjusting. Learning, as defined by Tortora and Grabowski (1996), is ?the ability to acquire new knowledge or skills through instruction or experience. Memory is the process by which that knowledge is retained over time.? The capacity of the brain to change with learning is plasticity. So how does the brain change with learning? According to Durbach (2000), there appear to be at least two types of modifications that occur in the brain with learning:

A change in the internal structure of the neurons, the most notable being in the area of synapses.

An increase in the number of synapses between neurons.

Initially, newly learned data are “stored” in short-term memory, which is a temporary ability to recall a few pieces of information. Some evidence supports the concept that short-term memory depends upon electrical and chemical events in the brain as opposed to structural changes such as the formation of new synapses. One theory of short-term memory states that memories may be caused by ?reverberating? neuronal circuits — that is, an incoming nerve impulse stimulates the first neuron which stimulates the second, and so on, with branches from the second neuron synapsing with the first. After a period of time, information may be moved into a more permanent type of memory, long-term memory, which is the result of anatomical or biochemical changes that occur in the brain (Tortora and Grabowski, 1996).

Injury-induced Plasticity: Plasticity and Brain Repair

During brain repair following injury, plastic changes are geared towards maximizing function in spite of the damaged brain. In studies involving rats in which one area of the brain was damaged, brain cells surrounding the damaged area underwent changes in their function and shape that allowed them to take on the functions of the damaged cells. Although this phenomenon has not been widely studied in humans, data indicate that similar (though less effective) changes occur in human brains following injury.

We will watch Brain story part 5, the developing brain for an excellent insight into this area.

An investigation into mirror neurons.

Probably the most fundamental breakthrough within the last ten years is research into what have become known as mirror neurons. Recent research has shown that these special neurons may play a vital role in the ability to learn from – as well as empathise with – another person.  A mirror neuron is a neuron that fires when a person (or animal) performs an action or the person or (animal) observes someone else doing the same action.  The mirror neuron  is so called because it “mirrors” the behaviour of another.

Like many great discoveries in science mirror neurons were discovered by accident.  Gallese et al. (1996) at the university of Parma in Italy, were carrying out research on motor neurons.  Because neural  messages are electrical in nature, they are able to hear the crackle of the electrical signal when the neuron was activated. See study on rhesus monkeys)

Marco Iacaboni (2004) asked participants to look at human faces while undergoing fMRI. the aim of the study was to see if  simply looking at the emotion expressed in someones’ face would cause the brain of the observer to be stimulated.  First the participants had to imitate the faces they were shown, and then they had to simply watch as they were shown the face s again.   (see below for visual)

Key researchers like Ramachandran have been looking at mirror neurons as a way to explain empathy to others. Mirror neurons appear to play a role in how people react to sports, theatre, and video games.  it appears that when we see a football player crushed by an opponent, we feel the contact of the hit thanks to our mirror neurons.  Researchers believe that mirror neurons have evolved to make us capable of understanding and interacting with fellow human beings.  Lets see; can you empaphise with these situations.

Remember a useful resource for this unit is “the brain from top to bottom” please take time surf your way around it should all start to make sense by now.

Examine one interaction between cognition and physiology on behaviour

Please read and make notes on the Richard Davidson study on p,47 of your study companion. I have an updated study from American scientific mind that we will discuss.

Excellent presentation again. Well done!!!!!!!!!! Not to mention the essays. great progress in your writing.


[Week beginning 20 October]

Discuss the use of brain imaging technologies in investigating the relationship between biological factors and behaviour.

The use of brain technology in brain research.

Modern research is now extensively used in neuropsychology because it provides  an opportunity to study an active brain. This allows researchers to see where specific brain processes take place and enables them to study localisation of brain function in the living human brain.

In your groups investigate and prepare a presentation of the following brain imaging techniques.

  • EEG
  • PET
  • FMRI

In relation to each method.  Identify a mental function and a specific study associated with each one. 

Revision of chapter 2.1

Half term- enjoy the break!!!!!!!!!!!!

[Week beginning 3 November]

The second part of the Biological level of analysis investigates ‘genetics and behaviour’. The key learning outcomes are:

  1. which genetics influence behaviour
  2. Examine one evolutionary explanation of behaviour.
  3. Discuss ethical considerations in research into genetic influences on behaviour.
Behaviour genetics.
Behavioural genetics deals with understanding how both genetics and the environment contribute to individual variations in human behaviour. It is interesting to note that humans share 93 per cent of genes with the rhesus macaque monkeys, even though humans do not look like or behave like these animals.  Although comparative psychology has revealed similarities between humans and monkeys, it is obvious that the seven per cent difference in the genetic materials account for a significant amount.  This example demonstrates the complexity of genetics, although the basic premise  of this field is that inheritance of DNA plays a role in behaviour, it is important not to misunderstand this.  What is inherited are the genes that give rise to the development of specific physiological processes that contribute to specific characteristics and behaviour.  it is not probable that a single gene is responsible for such complex behaviours as intelligence, criminal behaviour, altruism, or, attachment. Instead, what is inherited may be one of the building blocks for such complex behaviours.
  • Genetic research
  • Genetic research in humans is to a large extent based on correlation studies.  researchers look at how different variables may co-vary.  This means that a correlation study establishes that there has been a relationship between variables, but the researcher does not manipulate an independent variable as in an experiment.  Therefore, no cause and effect can be determined.

Inthinking study on depression.

Genetics and depression


[Week beginning 17th November.]
2.2 Biological level of analysis: genetics and behavior
  1. Discuss the extent to which genetics influence behaviour.

  2. Discuss ethical considerations in research into genetic influences on behaviour.

(Key principle) Human behaviour is, to some extent, genetically based. This means that behaviour can be explained by genetic inheritance, although this is rarely a full explanation since genetic inheritance should be seen as genetic predisposition which can be affected by environmental factors. Researchers interested in the genetic origin of behaviour often use twin studies so they can compare one twin with the other on a variable such as intelligence, depression or anorexia nervosa. this can be demonstrated by Bouchard et al (1990) who performed the Minnesota twin study, a longitudinal study investigating the relative role of genes in IQ.
Last week we looked at the concept of behavioural genetics and how it deals with our understanding of how both genetics and the environment contribute to individual variations in human behaviour. (the nature nurture debate) We looked introspectively at our personalites and physical make-up and discussed how alike we are to our parents, and to a certain extent tried to ascertain how much of who we are, is shaped by our genetics and our exposure to our environment. It is widely recognised that there must be some level of influence from each during our development.

We also discussed behaviour and some disorders that could fit into this diathesis model: First of all we started to look at depression (see handout).  We could also add autism, schizophrenia, Huntington’s disease and so on.  One of the key questions for psychology how can identify relevant research studies that give us an insight into how genetic inheritance influences our behaviour? (which we will look at next)
Finally, you were asked to research the Human Genome Project and how it can be expected that we will be treated to more and better informed longitudinal studies based on the knowledge gained from the project in future. It is widely agreed that it is unlikely that it will ever become ethically possible to conduct genetic experiments in humans, so we need to rely on data from twin studies, adoption studies and longitudinal studies. The majority of these are correlational in nature, and therefore we are unlikely to have 100 percent certainty that genes in combination are entirely responsible for any human behaviour.
A look at genetics and the environment; the diathesis stress model: see notes.
The diathesis stress model explains behaviour as both nature (genetic predisposition) and nurture (the environment).  The term ‘diathesis’ is used to refer to a genetic predisposition towards an abnormal condition.  It is our level of ability to cope the environmental stressors that may lead to disorders such as clinical depression or schizophrenia.  In the diathesis stress model, a biological or genetic vulnerability or predisposition (diathesis) interacts with the environment and life events (stressors) to trigger behaviours or psychological disorders. the greater the underlying vulnerability, the less stress is required to to trigger the behaviour or disorder.
Twin studies, family studies and adoption studies.
One of the most common  ways to study the possible correlation of genetic inheritance and behaviour is through twin research.
Researchers study twins because they share common genetic material. (see handout) Reading 3: Are you a natural?
Week beginning . [22 November]
An introduction into evolution theory.
Examine one evolutionary theory of behaviour.
Another principle which underpins the biological level of analysis is that the environment that the environment presents challenges to each individual.  this means that those who adapt best to the environment will have a greater chance of surviving, having children, and passing on their genes to their offspring.  This is the principle of Charles Darwins’ theory of evolution.
Darwins’ theory of natural selection explains how species acquire adaptive characteristics to survive  in an ever-changing environment.  According to the theory of natural selection, those members of a species who have characteristics which are better suited to the environment will be more likely to breed and thus pass on these traits.  in addition to arguing that traits may be handed down, Darwin laid the foundations for psychologists and biologists to study animals with the hope of gaining an insight into human behaviour.
Evolutionary psychology.
Evolutionary psychology is grounded on the principle that as genes mutate, those that are  advantageous are passed down through a process of natural selection. Evolutionary psychologists attempt to explain how certain human behaviours are testimony to the development of our species over time.  It is important to remember that natural selection cannot select a behaviour; it can only select for mechanisms that produce behaviour.  Lets look how Bart Simpson may have evolved.

Access powerpoint on evolution.
Ethical considerations in research into genetic influences of behaviour.
Week beginning