Biological Approach: Assumptions, Concepts, Genetics, and Inheritance

Assessment Objectives and Exam Guidance

AO1 - Knowledge and Understanding:
- Knowledge and understanding of psychological approaches, assumptions, concepts, and research.
- Key psychological terminology must be used accurately across all explanations.
AO2 - Application:
- Apply psychological knowledge and understanding of approaches by explaining the link between psychological assumptions, concepts, and research to behaviour in society within given contexts (scenarios).
- Scenario Application Sentence Structures:
- Direct Approach: "In this scenario…"
- Indirect Approach: "It may be that…"
- Combined Approach: "In this scenario… so it may be that…"

Biological Approach: Core Assumptions

Exam Requirement: Key assumptions of the biological approach must be learned word-for-word.
Assumption 1: Behaviour is influenced by the central nervous system, genes, and neurochemistry.
Assumption 2: Behaviour is a product of evolution.

Concept 1: The Influence of Biology on Behaviour and Traits

Core Question: How does biology impact or affect behaviour, such as personality?
Definition of Traits:
- Traits are defined as characteristics that make up an individual's personality.
- Traits possess three essential properties:
1. Stable
2. Consistent
3. Enduring (i.e., long-lasting)
Biological Basis of Personality:
- AO1 Identification (I): One influence of biology on behaviour is personality, specifically extraversion and introversion.
- AO1 Explanation (Ex): Personality has an innate, biological basis. Genes and neurochemistry influence extraversion/introversion because genes are inherited from parents and determine the degree of extraversion/introversion by regulating the activity of the nervous system.
- AO2 Application Starter: "This shows/explains how biological influence such as extraversion and introversion influence behaviour because…"
Extraversion:
- AO1 Identification (I): One influence of biology on behaviour is extraversion.
- AO1 Explanation (Ex): An individual who is an extravert has an under-active nervous system, which means that they thrive in social situations, are outgoing, and take risks.
- Traits of an Extravert:
1. Sociable
2. Friendly
3. Talkative
4. Adventurous
- AO2 Application Starter: "This shows/explains how biological influence such as extraversion influences behaviour because…"
Introversion:
- AO1 Identification (I): One influence of biology on behaviour is introversion.
- AO1 Explanation (Ex): An individual who is an introvert has an over-active nervous system, which means that they avoid the discomfort of arousing (activating) it any further by withdrawing and keeping away from exciting activities.
- Traits of an Introvert:
1. Uncomfortable in new situations
2. Withdrawn
3. Shy
4. Quiet
5. Prefer to spend time alone
- AO2 Application Starter: "This shows/explains how biological influence such as introversion influences behaviour because…"
The Extroversion–Introversion Continuum:
- Extraversion–introversion is a dimension of personality that exists on a continuum (i.e., along a continuous scale rather than in separate categorical boxes).

Concept 2: Genetics and Inheritance

Genes and Inheritance:
- Genes (AO1: I): A strand of DNA that has been inherited.
- Inherited (AO1: I): The passing on of genetic traits within DNA from one generation to the next.
Genotype:
- AO1 Identification (I): Genotype
- AO1 Explanation (Ex): An individual's genetic makeup that is present at birth.
- AO2 Application Starter: "This shows/explains how behaviour is influenced by a person's genotype because…"
Phenotype:
- AO1 Identification (I): Phenotype
- AO1 Explanation (Ex): An individual's interaction with the environment and their experiences.
- AO2 Application Starter: "This shows/explains how behaviour is influenced by a person's phenotype because…"
Genotype and Phenotype Relationship Formula:
- $\text{Genotype (genetic makeup)} + \text{Phenotype (environment and experiences)} = \text{Who you are}$
Sex Chromosomes:
- XX Chromosomes (AO1: I): The typical sex chromosome pattern found in females in humans (female sex chromosomes).
- AO2 Application Starter: "This shows/explains … because…"
- XY Chromosomes (AO1: I): The typical sex chromosome pattern found in males in humans (male sex chromosomes).
- AO2 Application Starter: "This shows/explains … because…"
The SRY Gene:
- AO1 Identification (I): The SRY gene
- AO1 Explanation (Ex): A specific gene contained on the Y chromosome. The presence of the SRY gene initiates a five-step developmental process:
1. Helps to develop male genitalia in prenatal development.
2. Ensures the individual is genetically male.
3. Causes the body to develop to be masculine.
4. Triggers the release of testosterone.
5. Masculinises the developing baby's brain.
- AO2 Application Starter: "This shows/explains how a male's behaviour is influenced by the SRY gene because…"

Key Terminology AO1 Expansion Summary

Traits: Characteristics making up personality that are stable, consistent, and enduring.
Extroversion: A personality trait driven by an under-active nervous system, leading individuals to seek environmental stimulation, take risks, and display sociable, friendly, talkative, and adventurous behaviors.
Introversion: A personality trait driven by an over-active nervous system, leading individuals to avoid additional nervous system arousal by withdrawing from high-stimulation activities and displaying quiet, shy, and solitary behaviors.
Genes: Strands of DNA inherited from parents containing encoded instructions for biological development and trait expression.
Genotype: The fundamental genetic constitution and gene combination present in an organism from birth.
Phenotype: The observable physical and behavioral traits of an organism resulting from the interaction between its genotype and environmental influences/experiences.
SRY Gene: Sex-determining Region Y gene located on the Y chromosome that triggers male gonadal development, testosterone secretion, physical masculinization, and brain masculinization during prenatal growth.

Comprehension Review Questions

What are the two main assumptions of the biological approach to behaviour?
According to the biological approach, traits are characteristics that make up a person's personality. They are: … (3 parts)
Define introvert.
Define extravert.
How might an under-active nervous system influence a person's behaviour as an extrovert?
How might an over-active nervous system influence a person's behaviour as an introvert?
What is meant by saying extraversion–introversion exists on a "continuum"?
What are genes?
What is the difference between genotype and phenotype? (include both definitions & comparative language e.g. whereas, unlike etc.).
Explain genotype and phenotype.
Female sex chromosomes =
Male sex chromosomes =
What is the role of the SRY gene in biological sex development? (5 parts)

Retrieval Grid and Assessment Framework

Biological Approach Core Assumptions [1 Mark Each]:
1. Behaviour is influenced by the central nervous system, genes, and neurochemistry [1 mark].
2. Behaviour is a product of evolution [1 mark].
Evaluation Points:
- Strength (+): Research support exists (e.g., Deady et al., 2006), which increases the overall validity of the biological approach [1 mark].
- Weakness (-): Ignores other psychological approaches; for instance, the MAOA-L gene is not present in 100% of offenders, demonstrating that other environmental or cognitive factors contribute [1 mark].
Key Concepts Specification Breakdown [1 Mark Each]:
- The influence of biology on behaviour and traits [1 mark]:
1. Extraversion [1 mark]
2. Introversion [1 mark]
- Genetics and inheritance [1 mark]:
1. Genes [1 mark]
2. Genotype [1 mark]
3. Phenotype [1 mark]
4. SRY gene [1 mark]
Spaced Retrieval Study Strategy:
- Continual reading and self-testing of pre-reading notes using "Look, Cover, Write, Check, Self-Assess" enables participation in lesson-based retrieval tasks without relying on written notes.