IB Psychology HL Paper 1
Mastering the Biological, Cognitive, and
Sociocultural Levels of Analysis Your Essential
Study Guide
Welcome to your comprehensive guide to the Biological, Cognitive, and Sociocultural Levels of
Analysis (BLOA, CLOA, SCLOA)! This guide breaks down key concepts with clear explanations and
real-world examples to help you ace your studies. Let's dive in
Biological Level of Analysis (BLOA)
1. Localisation of Function in the Brain
Question: Describe one study related to the localisation of function in the brain.
Answer: One classic study demonstrating the localisation of function is Sperry (1968), which
investigated the different roles of the brain hemispheres, particularly focusing on language. The theory
of localisation of function posits that specific areas of the brain are responsible for particular functions,
including behaviour, emotion, and thought.
Sperry (1968): Split-Brain Studies
Aim: To investigate the functional specialisation between the two brain hemispheres.
Method: Lab experiment with 11 participants who had their corpus callosum (the connection
between the hemispheres) severed due to severe epilepsy. Images or words were briefly (1/10th
of a second) presented to either their left or right visual field. Participants were then asked to
name or draw what they saw. Their results were compared to a control group with intact corpus
callosums.
Results: When information was presented to the left visual field, participants could recognise it
but not name it. They could only verbally identify information presented to the right visual field.
Conclusion: Sperry concluded that the left hemisphere is dominant for language processing
(including Broca's Area for language formulation), demonstrating the localisation of function.
💡 Study Tip: Remember that the left visual field is processed by the right hemisphere, and the right
visual field by the left hemisphere!
,2. Effects of Neurotransmitters on Human Behaviour
Question: Use one example to explain the effects of neurotransmitters on human behaviour.
Answer: The study by Higley et al. (1996) on rhesus monkeys provides an example of how the
neurotransmitter serotonin can affect aggression. Neurotransmitters are chemical messengers that
transmit signals between neurons, influencing our memories and thoughts.
Higley et al. (1996): Serotonin and Aggression in Monkeys
Aim: To investigate the role of serotonin levels on aggression.
Method: Natural lab experiment observing rhesus monkeys with varying serotonin levels
(measured using WINCS). The monkeys' interactions and fighting behaviours were observed.
Results: Monkeys with lower serotonin levels were more likely to be injured in fights, had
shorter lifespans, were more willing to engage in fights and take risks, and appeared more
fearless.
Conclusion: Higley et al. suggested that lower serotonin levels are linked to higher aggression,
possibly due to a lack of inhibition in the amygdala (a brain region associated with emotions).
🔑 Key Concept: Neurotransmitters play a crucial role in regulating a wide range of behaviours and
emotional responses.
3. Influence of Hormones on Human Behaviour
Question: Explain how hormones influence human behaviour.
Answer: Hormones, chemical messengers secreted by the endocrine system and transported via the
bloodstream, can significantly influence behaviour and thoughts by regulating various bodily functions.
The male hormone androgens, for instance, has been shown to affect the development of certain
behaviours.
Berenbaum & Hines (1992): Androgens and Play Behaviour in CAH Girls
Aim: To investigate the effect of excess androgens in the womb on the behaviour of girls with
Congenital Adrenal Hyperplasia (CAH).
Method: Researchers observed and interviewed girls with CAH (aged 3-12) and compared their
play behaviour and career aspirations with their non-CAH siblings. They were presented with
stereotypical male and female toys.
, Results: CAH girls showed a stronger preference for stereotypically male toys (like cars and
construction sets) and expressed interest in stereotypically male careers (like engineering and
piloting) compared to their non-CAH female siblings.
Conclusion: Berenbaum and Hines concluded that exposure to excess androgens during prenatal
development can influence brain organisation, leading to differences in later behaviour and
preferences.
🧠 Connect the Dots: Hormones can have long-lasting effects on development and behaviour.
4. Effect of the Environment on a Physiological Process
Question: Outline the effect of the environment on a physiological process.
Answer: The environment can significantly impact physiological processes, including brain
development. Rivkin et al.'s study demonstrated the effect of the prenatal environment on brain
plasticity. Brain plasticity refers to the brain's ability to change its structure and function in response to
new experiences or environmental changes.
Rivkin et al.: Prenatal Exposure and Brain Development
Aim: To investigate the long-term consequences of prenatal exposure to tobacco, cocaine, and
alcohol on brain development.
Method: MRI scans were conducted on 35 twelve-year-old participants whose prenatal exposure
to these substances was documented through longitudinal studies (Frank et al.).
Results: Participants exposed to tobacco, cocaine, and/or alcohol in the womb showed smaller
average brain size and reduced cortical brain matter compared to the average for their age.
The effects were also found to be cumulative.
Conclusion: Rivkin et al. concluded that prenatal exposure to these substances can have lasting
negative consequences on brain structure.
🌱 Think About It: The environment, even before birth, plays a critical role in shaping our physiology.
5. Brain Scanning Technologies
Question: Explain the use of one brain scanning technology.
Answer: Magnetic Resonance Imaging (MRI) is a brain scanning technology that uses radio waves
and a powerful magnetic field to create detailed structural images of the brain and its components.
, How it works: MRI detects the water molecules in different brain tissues. The magnetic field
aligns the protons in these molecules, and radio waves then briefly disrupt this alignment. As the
protons realign, they emit signals that are detected by the scanner and used to create detailed
images.
Application in research: MRI allows psychologists to investigate the biological underpinnings
of behaviour by identifying structural abnormalities or variations in brain regions associated with
specific functions. For example, Rivkin et al. used MRI to identify structural changes in the
brains of children exposed to substances prenatally.
📸 Visualise: MRI provides a static, high-resolution snapshot of the brain's anatomy.
6. Evolutionary Explanation of Behaviour
Question: Explain one evolutionary explanation of behaviour.
Answer: The Parental Investment Theory offers an evolutionary explanation for certain mating
behaviours. Evolution, driven by natural selection, favours traits that enhance survival and
reproduction. This theory suggests that the sex that invests more time and resources in reproduction
(typically females) will be more selective in choosing mates, while the sex that invests less (typically
males) will be more inclined to seek multiple partners to increase their gene pool's spread.
Hadfield & Clarke (1990): Sexual Offers on Campus
Aim: To investigate gender differences in responses to sexual invitations.
Method: Male and female confederates (average age 22) approached university students (48
males and females) and asked one of three questions: "Will you go on a date with me?", "Will
you go to my apartment?", or "Will you have sex with me?".
Results:
o Date: 56% of females and 50% of males agreed.
o Apartment: 69% of males agreed, but only 6% of females.
o Sex: 75% of males agreed, while 0% of females agreed.
Conclusion: Hadfield and Clarke concluded that males are significantly more likely to accept
casual sexual invitations than females, supporting the parental investment theory.
🧠 Evolutionary Lens: Our behaviours can be understood in the context of our evolutionary history and
reproductive strategies.
7. Principle of the Biological Level of Analysis
Mastering the Biological, Cognitive, and
Sociocultural Levels of Analysis Your Essential
Study Guide
Welcome to your comprehensive guide to the Biological, Cognitive, and Sociocultural Levels of
Analysis (BLOA, CLOA, SCLOA)! This guide breaks down key concepts with clear explanations and
real-world examples to help you ace your studies. Let's dive in
Biological Level of Analysis (BLOA)
1. Localisation of Function in the Brain
Question: Describe one study related to the localisation of function in the brain.
Answer: One classic study demonstrating the localisation of function is Sperry (1968), which
investigated the different roles of the brain hemispheres, particularly focusing on language. The theory
of localisation of function posits that specific areas of the brain are responsible for particular functions,
including behaviour, emotion, and thought.
Sperry (1968): Split-Brain Studies
Aim: To investigate the functional specialisation between the two brain hemispheres.
Method: Lab experiment with 11 participants who had their corpus callosum (the connection
between the hemispheres) severed due to severe epilepsy. Images or words were briefly (1/10th
of a second) presented to either their left or right visual field. Participants were then asked to
name or draw what they saw. Their results were compared to a control group with intact corpus
callosums.
Results: When information was presented to the left visual field, participants could recognise it
but not name it. They could only verbally identify information presented to the right visual field.
Conclusion: Sperry concluded that the left hemisphere is dominant for language processing
(including Broca's Area for language formulation), demonstrating the localisation of function.
💡 Study Tip: Remember that the left visual field is processed by the right hemisphere, and the right
visual field by the left hemisphere!
,2. Effects of Neurotransmitters on Human Behaviour
Question: Use one example to explain the effects of neurotransmitters on human behaviour.
Answer: The study by Higley et al. (1996) on rhesus monkeys provides an example of how the
neurotransmitter serotonin can affect aggression. Neurotransmitters are chemical messengers that
transmit signals between neurons, influencing our memories and thoughts.
Higley et al. (1996): Serotonin and Aggression in Monkeys
Aim: To investigate the role of serotonin levels on aggression.
Method: Natural lab experiment observing rhesus monkeys with varying serotonin levels
(measured using WINCS). The monkeys' interactions and fighting behaviours were observed.
Results: Monkeys with lower serotonin levels were more likely to be injured in fights, had
shorter lifespans, were more willing to engage in fights and take risks, and appeared more
fearless.
Conclusion: Higley et al. suggested that lower serotonin levels are linked to higher aggression,
possibly due to a lack of inhibition in the amygdala (a brain region associated with emotions).
🔑 Key Concept: Neurotransmitters play a crucial role in regulating a wide range of behaviours and
emotional responses.
3. Influence of Hormones on Human Behaviour
Question: Explain how hormones influence human behaviour.
Answer: Hormones, chemical messengers secreted by the endocrine system and transported via the
bloodstream, can significantly influence behaviour and thoughts by regulating various bodily functions.
The male hormone androgens, for instance, has been shown to affect the development of certain
behaviours.
Berenbaum & Hines (1992): Androgens and Play Behaviour in CAH Girls
Aim: To investigate the effect of excess androgens in the womb on the behaviour of girls with
Congenital Adrenal Hyperplasia (CAH).
Method: Researchers observed and interviewed girls with CAH (aged 3-12) and compared their
play behaviour and career aspirations with their non-CAH siblings. They were presented with
stereotypical male and female toys.
, Results: CAH girls showed a stronger preference for stereotypically male toys (like cars and
construction sets) and expressed interest in stereotypically male careers (like engineering and
piloting) compared to their non-CAH female siblings.
Conclusion: Berenbaum and Hines concluded that exposure to excess androgens during prenatal
development can influence brain organisation, leading to differences in later behaviour and
preferences.
🧠 Connect the Dots: Hormones can have long-lasting effects on development and behaviour.
4. Effect of the Environment on a Physiological Process
Question: Outline the effect of the environment on a physiological process.
Answer: The environment can significantly impact physiological processes, including brain
development. Rivkin et al.'s study demonstrated the effect of the prenatal environment on brain
plasticity. Brain plasticity refers to the brain's ability to change its structure and function in response to
new experiences or environmental changes.
Rivkin et al.: Prenatal Exposure and Brain Development
Aim: To investigate the long-term consequences of prenatal exposure to tobacco, cocaine, and
alcohol on brain development.
Method: MRI scans were conducted on 35 twelve-year-old participants whose prenatal exposure
to these substances was documented through longitudinal studies (Frank et al.).
Results: Participants exposed to tobacco, cocaine, and/or alcohol in the womb showed smaller
average brain size and reduced cortical brain matter compared to the average for their age.
The effects were also found to be cumulative.
Conclusion: Rivkin et al. concluded that prenatal exposure to these substances can have lasting
negative consequences on brain structure.
🌱 Think About It: The environment, even before birth, plays a critical role in shaping our physiology.
5. Brain Scanning Technologies
Question: Explain the use of one brain scanning technology.
Answer: Magnetic Resonance Imaging (MRI) is a brain scanning technology that uses radio waves
and a powerful magnetic field to create detailed structural images of the brain and its components.
, How it works: MRI detects the water molecules in different brain tissues. The magnetic field
aligns the protons in these molecules, and radio waves then briefly disrupt this alignment. As the
protons realign, they emit signals that are detected by the scanner and used to create detailed
images.
Application in research: MRI allows psychologists to investigate the biological underpinnings
of behaviour by identifying structural abnormalities or variations in brain regions associated with
specific functions. For example, Rivkin et al. used MRI to identify structural changes in the
brains of children exposed to substances prenatally.
📸 Visualise: MRI provides a static, high-resolution snapshot of the brain's anatomy.
6. Evolutionary Explanation of Behaviour
Question: Explain one evolutionary explanation of behaviour.
Answer: The Parental Investment Theory offers an evolutionary explanation for certain mating
behaviours. Evolution, driven by natural selection, favours traits that enhance survival and
reproduction. This theory suggests that the sex that invests more time and resources in reproduction
(typically females) will be more selective in choosing mates, while the sex that invests less (typically
males) will be more inclined to seek multiple partners to increase their gene pool's spread.
Hadfield & Clarke (1990): Sexual Offers on Campus
Aim: To investigate gender differences in responses to sexual invitations.
Method: Male and female confederates (average age 22) approached university students (48
males and females) and asked one of three questions: "Will you go on a date with me?", "Will
you go to my apartment?", or "Will you have sex with me?".
Results:
o Date: 56% of females and 50% of males agreed.
o Apartment: 69% of males agreed, but only 6% of females.
o Sex: 75% of males agreed, while 0% of females agreed.
Conclusion: Hadfield and Clarke concluded that males are significantly more likely to accept
casual sexual invitations than females, supporting the parental investment theory.
🧠 Evolutionary Lens: Our behaviours can be understood in the context of our evolutionary history and
reproductive strategies.
7. Principle of the Biological Level of Analysis
