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The Bases of Human Behaviour – Class 11 Psychology notes, important questions and MCQs

NCERT Class 11 Psychology, chapter 3. Notes, key terms, important questions with answers and MCQs.

Chapter overview

Human behaviour has biological and socio-cultural bases. Evolution has shaped our characteristics, the nervous system and endocrine glands control behaviour, and heredity passes traits through genes. At the same time, culture, socialisation, enculturation and acculturation shape how people think and act. Behaviour results from the interaction of biology and environment.

Biological bases

The nervous system has the central nervous system (brain and spinal cord) and the peripheral nervous system (somatic and autonomic); the autonomic system has sympathetic (prepares for emergency, 'fight or flight') and parasympathetic (calms the body) divisions.
The neuron is the basic unit, with dendrites, cell body, axon and terminal buttons; messages pass through synapses using neurotransmitters.
The brain has the hindbrain (medulla, pons, cerebellum), midbrain and forebrain (cerebral cortex, thalamus, hypothalamus, limbic system); the cortex has frontal, parietal, temporal and occipital lobes. Endocrine glands such as the pituitary (master gland), thyroid, adrenal and pancreas release hormones.

Heredity and culture

Genes on chromosomes carry hereditary information; humans have 23 pairs of chromosomes; a person's genetic make-up is the genotype and observable traits the phenotype.
Culture is the human-made part of the environment, with material and subjective aspects; socialisation is learning the skills and values of a society, and enculturation is learning one's own culture, often without being aware of it.
Acculturation is the change that results from contact with another culture; strategies include integration, assimilation, separation and marginalisation (J. W. Berry).

Key terms

Neuron: the basic cell of the nervous system that transmits information
Synapse: the gap between two neurons where messages are passed
Neurotransmitter: a chemical that carries messages across a synapse
Endocrine gland: a ductless gland that releases hormones into the blood
Acculturation: cultural and psychological change from contact with another culture

Important questions with answers

What is a synapse?2 marks

A synapse is the small gap between the terminal of one neuron and the dendrite or cell body of another. Messages are passed across it by chemicals called neurotransmitters.

Distinguish between the sympathetic and parasympathetic nervous systems.3 marks

Both are divisions of the autonomic nervous system. The sympathetic system prepares the body for emergencies, increasing heart rate, breathing and blood sugar ('fight or flight'). The parasympathetic system calms the body after an emergency and conserves energy, slowing heart rate and aiding digestion.

Explain the structure and functions of the human brain.5 marks

The brain is the main organ of the central nervous system and is divided into three parts. The hindbrain includes the medulla oblongata, which controls breathing, heart rate and other vital functions; the pons, which connects parts of the brain and is involved in sleep; and the cerebellum, which coordinates movement, balance and posture and stores memories of motor skills. The midbrain, small in size, is involved in vision and hearing reflexes and in arousal through the reticular activating system. The forebrain is the largest part. Its cerebral cortex, divided into two hemispheres connected by the corpus callosum, controls higher mental functions such as thinking, language, planning and problem solving. Each hemisphere has four lobes: the frontal lobe, involved in planning, decision-making and voluntary movement; the parietal lobe, involved in touch and body sensations; the temporal lobe, involved in hearing and memory; and the occipital lobe, involved in vision. The thalamus acts as a relay station for sensory information, the hypothalamus regulates hunger, thirst, temperature, sex and emotions and controls the pituitary gland, and the limbic system, including the hippocampus and amygdala, is involved in memory and emotion. The left hemisphere is usually more involved in language and the right in spatial tasks, although both work together.

Quick revision

Evolution and biological bases.
Nervous system, neuron, brain parts.
Endocrine glands and hormones.
Heredity; culture, socialisation, enculturation, acculturation.

Exam tips

Draw and label a neuron.
Remember: sympathetic = fight or flight; parasympathetic = rest and digest.

Practice MCQs

The basic unit of the nervous system is the
1. neuron
2. gland
3. chromosome
4. hormone
Show answer
Answer: (a) neuron. It transmits information.
The 'master gland' is the
1. pituitary
2. thyroid
3. adrenal
4. pancreas
Show answer
Answer: (a) pituitary. It controls other glands.
Humans have how many pairs of chromosomes
1. 21
2. 46
3. 23
4. 24
Show answer
Answer: (c) 23. There are 46 chromosomes in all.
The division that prepares the body for 'fight or flight' is the
1. sympathetic system
2. parasympathetic system
3. somatic system
4. central nervous system
Show answer
Answer: (a) sympathetic system. Heart rate rises.
The part of the brain that coordinates balance and movement is the
1. medulla
2. occipital lobe
3. thalamus
4. cerebellum
Show answer
Answer: (d) cerebellum. It is in the hindbrain.
The visual area of the cortex is mainly in the
1. frontal lobe
2. parietal lobe
3. temporal lobe
4. occipital lobe
Show answer
Answer: (d) occipital lobe. It is at the back of the brain.
Learning one's own culture, often without being aware of it, is called
1. acculturation
2. assimilation
3. enculturation
4. marginalisation
Show answer
Answer: (c) enculturation. It happens through observation and participation.
In Berry's model, keeping one's own culture while also participating in the larger society is
1. assimilation
2. separation
3. integration
4. marginalisation
Show answer
Answer: (c) integration. It is often the most adaptive strategy.

All chapters of Class 11 Psychology

Written by Kundali IQ from standard, well-established facts to help with revision. This is not an official NCERT publication; always read your textbook too.