Biological Perspective Study Guide
Overview
The biological perspective in psychology focuses on how our biology—genes, brain
structure, nervous system, and hormones—shapes our thoughts, feelings, and behaviours. It
emphasizes nature over nurture, arguing that much of who we are is determined before
birth.
Gesell's Theory of Maturation
Arnold Gesell believed that development follows a natural sequence dictated by genetic
programming. He proposed that children mature through predetermined stages that are
relatively unaffected by the environment. His research formed the basis for developmental
milestones used in pediatric and educational settings today.
Impact of Genetics on Behaviour
Genes can influence personality, health, and predisposition to certain behaviours or
disorders. Some examples include:
- Huntington's Disease: A dominant genetic disorder affecting movement, memory, and
mood.
- Cystic Fibrosis: A life-limiting condition that affects the lungs and digestion.
- Sickle Cell Disease: Alters red blood cell shape and can cause pain and fatigue, influencing
emotional and social behaviours.
Role of the Nervous System and Hormones
The central nervous system (brain and spinal cord) regulates vital bodily functions and
emotional reactions. The autonomic nervous system includes:
- Sympathetic branch: Prepares the body for stress ('fight or flight').
- Parasympathetic branch: Calms the body ('rest and digest').
Hormones also impact behaviour:
- Melatonin: Regulates sleep.
- Testosterone: Linked to aggression.
- Oxytocin: Promotes bonding.
- Cortisol: Increases during stress.
Overview
The biological perspective in psychology focuses on how our biology—genes, brain
structure, nervous system, and hormones—shapes our thoughts, feelings, and behaviours. It
emphasizes nature over nurture, arguing that much of who we are is determined before
birth.
Gesell's Theory of Maturation
Arnold Gesell believed that development follows a natural sequence dictated by genetic
programming. He proposed that children mature through predetermined stages that are
relatively unaffected by the environment. His research formed the basis for developmental
milestones used in pediatric and educational settings today.
Impact of Genetics on Behaviour
Genes can influence personality, health, and predisposition to certain behaviours or
disorders. Some examples include:
- Huntington's Disease: A dominant genetic disorder affecting movement, memory, and
mood.
- Cystic Fibrosis: A life-limiting condition that affects the lungs and digestion.
- Sickle Cell Disease: Alters red blood cell shape and can cause pain and fatigue, influencing
emotional and social behaviours.
Role of the Nervous System and Hormones
The central nervous system (brain and spinal cord) regulates vital bodily functions and
emotional reactions. The autonomic nervous system includes:
- Sympathetic branch: Prepares the body for stress ('fight or flight').
- Parasympathetic branch: Calms the body ('rest and digest').
Hormones also impact behaviour:
- Melatonin: Regulates sleep.
- Testosterone: Linked to aggression.
- Oxytocin: Promotes bonding.
- Cortisol: Increases during stress.
