Bases of Human Behaviour

BASES OF HUMAN BEHAVIOUR

​EVOLUTIONARY PERSPECTIVE

• The uniqueness of individuals results from the interaction of their genetic endowments and environmental demands.

• Biologists believe that these species have evolved to their present form from their pre-existing form.

• Evolution refers to gradual and orderly biological changes that result in a species from their pre-existing forms in response to the changing adaptational demands of their environment. It occurs through process of natural selection.

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• Fitness is the ability of an organism to survive and contribute it's genes to the next generation.

• Three important features of modern human beings differentiate them from their ancestors:

1. A bigger and developed brain with increased capacity for cognitive behaviours

2. Ability to walk upright on two legs

3. A free hand with a workable opposing thumb.

Multiple Choice

1._____ is the ability of an organism to survive and contribute it's genes to the next generation. 

• Fitness

• Evolution

BIOLOGICAL AND CULTURAL ROOTS OF BEHAVIOUR

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• An important determinant of our behaviour is the biological structures that we have inherited from ourancestors in the form of developed body and brain.

• All of us negotiate our lives with the culture in which we are born and brought up and it provides us with different experiences and opportunities of learning by putting us in a variety of situations or placing different demands on our lives.

​NUERONS

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• It's the basic unit of our nervous system.

• They are specialised cells, which converts various forms of stimuli into electrical impulses and are also specialised for reception, conduction and transmission of information in the form of electrochemical signals.

• They receive informationfrom sense organs or from other adjacent neurons, carry them to the central nervous system and bring motor information from the central nervous system to the motor organs.

• Three fundamental components: soma, dendrites, axon

Multiple Choice

Which is not the fundamental components of neurons :

• Dendrites

• Soma

• Synapse

• Axon

​SOMA

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• Main body of the nerve cell.

• Contains nucleus of the cell, other structures common to living cells of all types and most of the cytoplasm of the neuron.

• Genetic material of the neuron is stored inside the nucleus and active during cell reproduction and protein synthesis

DENDRITES​

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• They are the branch like specialised structure emanating from the soma.

• Recieving ends of a neuron.

• Recieve the incoming neural impulses from the adjacent neurons or directly from the sense organs.

• They have specialised receptors which become active when a signal arrives in electrochemical or biochemical form.

• The recieved signals are passed on to soma and then to axon so that the information is relayed to another neauron or to muscles.

​AXON

​ • It conduct the information along its length, which can be several feet in the spinal cord and less than a millimetre in the brain.

• At the terminal point it branches into small structures called terminal buttons which can transmit information to another neuron, gland and muscle.

• Neurons generally conduct information in one direction: from dendrites through soma and axon to the terminal buttons.

Multiple Choice

____ is the basic unit of our nervous system

• Dendrites

• Soma

• Nuerons

• Nerves

Multiple Choice

_____ is the main body of the nerve cell.

• Axon

• Nerve impulse

• Dendrites

• Soma

Multiple Choice

____ are the recieving ends of the neurons

• Axon

• Dendrites

• Nerve impulse

• Soma

Multiple Choice

At the terminal point axon branches into small structures called _____.

• Synapse

• Dendrites

• Terminal buttons

• Nuerotransmittor

NERVES​

• ​ Nerves are bundle of axons which conduct information from one place to another in nervous system.

• Two types : sensory and motor.

• Sensory nerves: Also called afferent nerves, carry information from sense organs to central nervous system.

• Motor nerves: Also called efferent nerves, carry information from central nervous system to muscles or glands . It conduct neural commands which direct, control and regulates our movement and other responses.

• There are mixed nerves also.

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​NERVE IMPULSE

• ​ Information travel within the nervous system in the form of nerve impulses.

• When stimulus energy comes into contact with receptors, electrical changes in the nerve potential start.

• Nerve potential is the sudden change in the electrical potential of the surface of the neuron e

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• When the stimulus energy is relatively weak, we donot feel the stimulus and if the stimulus energy is strong then electrical impulses are generated and conducted towards the central nervous system.

• The strength of the nerve impulse doesnot depend on the strength of the stimulus that started the impulse.

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• The strength of the nerve impulse remain constant in nerve fibres.

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​SYNAPSE

​ • A single neuron can carry a neural impulse up to a distance covered by the length of its axon. 

• A number of neurons participate when the impulse is to be conducted to distant parts.

• The axon tip of a preceding neuron make functional connections or synapse with dendrites of the other neuron.

• A neuron is never physically connected to other neuron. They have small gaps in between two called synaptic cleft.

• The conduction of neural impulse in the axon is electrochemical, while the nature of synaptic transmission is chemical which is known as neurotransmitter

Multiple Choice

Sensory nerves are also called efferent nerves. True/False.  

• TRUE

• FALSE

Multiple Choice

Small gap in between two neurons are called ____. 

• Synaptic cleft

• Nuerotransmittor

• Nerve impulse

• Synapse

​The nervous system

​CLASSIFICATION OF NERVOUS SYSTEM

• ​ Human nervous system is the most complex and most developed of all living creatures.

• Based on location,the nervous system can be divided into two parts:Central Nervous System[CNS] and Peripheral Nervous System[PNS].

​PERIPHERAL NERVOUS SYSTEM

• ​The PNS provide information to the CNS from sensory receptors and relays back motor commands from the brain to the muscles and glands.

• The PNS is composed of all the neurons and nerve fibres that connect the CNS to the rest of the body.

• ​The PNS is divided into Somatic nervous system and Autonomic nervous system.

• ​The autonomic nervous system is further divided into Sympathetic and Parasympathetic systems.

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​SOMATIC NERVOUS SYSTEM

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• This system consistes of two types of nerves called cranial nerves and spinal nerves.

• There are  12 sets ofcranial nerves.

• Also there are 3 types of cranial nerves;sensory,motor and mixed.

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• The sensory nerves collect information from receptors of the head region and carry them to the brain.

• ​The motor nerves carry motor impulses originating from the brain to muscles of the head region.

• ​Mixed nerves have both sensory and motor fibres,which conduct sensory and motor information to and from the brain.

• ​There are 31 sets of spinal nerves.Each set has sensory and motor nerves.

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​FUNCTIONS OF SPINAL NERVES

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• The sensory fibres of the spinal nerves collect sensory information from all over the body and send them to the spinal cord from where they are then carried out to the brain.

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• The motor impulses coming down from the brain are sent to the muscles by the motor fibres of the spinal nerves.

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​THE AUTONOMIC NERVOUS SYSTEM

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• This system governs activities which are not under the control of the individuals; like breathing, blood circulation, salivation, stomach contraction and emotional reactions.

• The autonomic nervous system has two divisions; Sympathetic and Parasympathetic division

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SYMPATHETIC DIVISION

Deals with emergencies when the action must be quick and powerful,such as in situations of fight or flight.

​PARASYMPATHETIC DIVISION

When the emergency is over the Parasympathetic division takes over;it accelerates the sympathetic division and calms down the individualto normal condition.

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​THE CENTRAL NERVOUS SYSTEM

• ​ The central nervous system is the centre of all neural activity.

• It integrates all incoming sensory information, performs all kinds of cognitive activities and issues motor commands to muscles and glands.

• The CNS comprises of the Brain and Spinal cord.

STRUCTURE OF THE BRAIN ​

​ The brain can be divided into three parts:

• Hindbrain

• Midbrain

• Forebrain

​HINDBRAIN

​Medulla Oblongata

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• It is the lowest part of the brain that exists in continuation of the spinal cord.

• ​It contains neural centres ,which regulate basic life supporting activities like breathing,heart rate and blood pressure.This is why Medulla Oblongata is known as the vital centre of the brain.

• ​It has some centres of autonomic activities also.

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ØPons

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• ​It is connected with medulla on one side and midbrain on the other.

• ​Pons receives auditory signals relayed by our ears.

• ​It is involved in sleep mechanism, respiratory movement and facial expressions also

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Cerebellum

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• Highly developed part of the hindbrain.

• ​Maintains and controls posture and equilibrium of the body.

• ​Coordination of muscular movements.

• ​Also stores the memory of movement patterns so that we do not have to concentrate on how to walk,dance or ride a bicycle.

​MIDBRAIN

• ​ It is small in size and connects hindbrain with the forebrain.

• An important part of midbrain is Reticular Activating System(RAS),which is responsible for our arousal. It makes us alert and active by regulating sensory inputs. Also helps in selecting information from the environment.

Multiple Choice

Which of the following is involved in sleep mechanism, particularly the sleep characterised by brain

• Cerebellum

• Midbrain

• Medulla Oblangata

• Pons

​FOREBRAIN

​Most important part of the brain because it performs all cognitive, emotional and motor activities

Hypothalamus

• One of the smallest structures in the brain.

• Plays vital role in our behaviour.

• Involved in emotional and motivational behaviours such as eating, sleeping ,temperature regulation and sexual arousal.

• Regulates and controls internal environment of the body and regulates secretion of hormones from various endocrine glands.

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​Thalamus

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• ​ Situated on ventral side of the hypothalamus.

• It is like a relay station that receives all incoming sensory signals from sense organs and sends them to appropriate parts of cortex.

• Also receives all outgoing signals coming from the cortex and sends them to approprote parts of body.

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​The Limbic System

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• It helps in maintaining internal homeostasis by regulating body temperature, blood pressure and blood sugar level.

• ​Limbic system comprises of hippocampus and amygdala.

• ​Hippocampus plays and important role in long-term memory.

• The amygdala plays an important role in emotional behaviour.

​Cerebrum

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• Also known as cerebral cortex.

• This part regulates  all higher levels of cognitive functions such as attention, perception, learning, memory, language, behaviour, reasoning and problem solving.

• The cerebrum is divided into two symmetrical halves called the cerebral hemispheres.

• ​ Left hemisphere usually controls language behaviour.

• The right hemisphere is usually specialised to deal with images,spatial relationships and pattern recognition.

• These two hemispheres are connected by a white bundle of myelinated fibres called corpus callosum which carries messages back and forth between the hemispheres.

Multiple Choice

Internal environment of the body is regulated and controlled by

• Midbrain

• Hypothalamus

• Thalamus

• Limbic System

Multiple Choice

Which of the following are known as relay station of the brain

• Forebrain

• Thalamus

• Hypothalamus

• Midbrain

LOBES OF THE CEREBRAL CORTEX​

• ​ Cerebral cortex is also didvided into four lobes: Frontal Lobe, Parietal Lobe, Temporal Lobe, Occipatal Lobe.

• Frontal lobe is mainly concerned with cognitive functions such as attention, thinking, memory learning, and reasoning.

• The Parietal lobe is concerned with cutaneous sensations and their coordination with visual and auditory sensations.

• Temporal lobe is concerned with processing of auditory information.

  The occipital lobe is concerned with visual information.

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​SPINAL CORD

• ​ The spinal cord plays the role of a huge cable  which exchange innumerable messages with the CNS

• Two main functions of the spinal cord :-

1. It carries sensory impulses coming from lower parts of the body to the brain and motor impulses originating from the brain to all over the body.

2. It performs some simple reflexes that do not involve the brain.

​REFLEX ACTION

• ​ A Reflex Action is an involuntary action that occurs very quickly after its specific kind of stimulation.

• It takes place automatically without conscious decision of the brain.

• Example; eye-blinking reflex.

• Most reflex actions are carried out by the spinal cord and do not involve the brain.

Multiple Choice

Which of the following is concerned with the cognitive processes like thinking, attention, memmory etc

• Parietal lobe

• Temporal lobe

• Frontal lobe

• Occupital lobe

Multiple Choice

Which of the following is/are reflex action(s)

• knee jerks

• Pupil constriction

• Breathing

• All of the above

​ENDOCRINE SYSTEM

• ​ The endocrine glands play a crucial role in our development and behaviour. They secrete hormones which control some of our behaviour.

• They are also called ductless glands because they do not have any duct to send their secretions.  Hormones are circulated by the blood stream

• When endocrine glands work in conjugation with nervous system, it is called neuroendocrine system

​Pituitary Gland

• ​ Pituitary gland is situated within the cranium just below the hypothalamus.

• Pituitary gland secretes the growth hormone and many other hormones, which direct and regulate the secretions of many other endocrine glands found in our body. This is why the pituitary gland is known as the “master gland”.

• It is divided into :-

1. Anterior pituitary – directly connected to hypothalamus

2. Posterior pituitary

​Thyroid Gland

• ​ Thyroid gland is located in the neck. It produces thyroxin that influences the body’s metabolic rate. Optimum amount of thyroxin is secreted and regulated by the Thyroid Stimulating Hormone.

• The steady secretion of TSH maintains the production of energy, consumption of oxygen and elimination of wastes in body cells

• Underproduction of thyroxin leads to physical and psychological lethargy

Multiple Choice

The endocrine gland directly connected to the hypothalamus is

• Anterior pitutary

• Posterior pituitary

• Thyroid gland

• None of these

Multiple Choice

Underproduction of ----------- causes physical and psychological lethargy

• Growth hormone

• TSH

• Thyroxine

• Adrenalin

​Adrenal Gland

​ Adrenal gland is located above each kidney. It has two parts :-

• Adrenal cortex – It’s secretion of is controlled and regulated by Adrenocorticotrophic Hormone. It secretes a group of hormones called corticoids, which are utilised by the body for a number of physiological purpose

• Adrenal medulla – It secretes two hormones  named epinephrine and norepinephrine. Sympathetic activation and stimulation of hypothalamus are it’s main functions.

​Pancreas

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• The pancreas  has a primary role in digestion of food and it also secretes a hormone known as insulin

• Insulin helps the liver to break down glucose

• Underproduction of insulin causes Diabetes

​Gonads

• ​ Gonads refer to testes in males and ovaries in females. The hormones secreted by these glands control and regulate sexual behaviours and reproductive functions of males and females

• Secretion of hormones of these glands is regulated by a hormone called gonadotrophic hormone

• The ovaries in females produce estrogen and progesterone. Estrogen guide the sexual development of the female body. Progesterone  is involved in preparation of uterus for the possible reception of fertilised ovum

• Testes in males produce sperm continuously and secrete male sex hormones called androgens. The major androgen is testosterone

Multiple Choice

Which of the following is/are hormone(s) secreted by adrenal gland

• Epinephrine

• Norepinephrine

• Corticoids

• All of these

Multiple Choice

Which of the following is/are the hormone(s) produced by the gonads

• Estrogen

• Androgen

• Insulin

• Both (1) & (2)

​HEREDITY

• ​We inherit characteristics from our parents in the form of genes.

• The study of the inheritance of physical and psychological characteristics from ancestors is referred to as genetics

​Chromosomes

• ​Chromosomes are the hereditary elements of the body. They are thread – like paired structures in the nucleus of each cell

• The gametic cells (sperm and ovum) have 23 chromosomes but not in pairs

• At the time of conception, the organism inherits 46 chromosomes from parents, 23 from the mother and 23 from the father

• The 23rd chromosome of the sperm cell can be either the capital X or Y typet. If the X type sperm fertilises the egg cell, the fertilised egg will have an XX 23rd chromosome pair, and the child will be a female. On the other hand, if a Y type sperm fertilises the egg, the 23rd chromosome pair will be XY, and the child will be a male

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​Genes

​ Every chromosome stores thousands of genetic commands in the form of genes. They contain instructions for the production of specific proteins, which regulate the body’s physiological processes and the expression of phenotypic traits. The observable traits of an organism are called phenotype

The traits, which can be passed on to the offspring through genetic material are called its genotype.

A given gene can exist in several different forms. Change of a gene from one form to another is called mutation.

Multiple Choice

Characteristics are inherited from one generation to the next through

• Chromosomes

• DNA

• RNA

• Genes

Multiple Choice

A sperm carrying a Y chromosome fertilises an egg to produce a zygote. The child born will be

• male

• female

​INFLUENCE OF CULTURE IN OUR BEHAVIOUR

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• Biological factors alone cannot help us in understanding behaviour.

  The people, society and culture around us have a huge role in our behaviour.

• For example, Food habits of a person living in a village and that of a person living in a city may differ

• Culture refers to the man-made part of the environment.

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​CULTURE

​ •Culture includes behavioural products of others who preceded us.

•Culture is already there as we begin life.

•It contains values that will be expressed and a language to express them.

•It contains a way of life that will be followed by most of us who grow up in that context.

​Culture and Society

• ​ Culture is the label for all the different features that vary from society to society.

• A society is a group of people who occupy a particular territory and speak a common language not generally understood by neighbouring people

• A society may or may not be a single nation, but every society has its own culture and it is culture that shapes human behaviour from society to society.​

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Multiple Choice

    Culture refers to :

 

• Man-made part of environment

• Artificial part of environment

• Artificial part of nature

• Man-made of nature

​ENCULTURATION

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• Enculturation refers to all learning that takes place without direct, deliberate teaching.

• A key element of enculturation is learning by observation

SOCIALISATION

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• Socialisation is the process by which individuals acquire knowledge, skills, and dispositions which enable them to participate as effective members of groups and society

• Any one who possesses power relative to us can socialize us. Such people are called socialising agents.

• Parents, school, peer groups and media are some of the socialising agents.

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​ACCULTURATION

• ​ Acculturation refers to cultural and psychological changes resulting from contact with other cultures.

• Changes due to acculturation may be examined at objective and subjective levels.

• At the subjective level, changes are often reflected in people’s attitudes towards change. They are referred to as acculturation attitudes.

• At the objective level, changes are often reflected in people’s day-to-day behaviours and activities. These are referred to as acculturation strategies

​Acculturation Strategies

​ Integration: Interest in both, maintaining one’s original culture and identity, while staying in daily interaction and other cultural groups.

Assimilation: People do not wish to maintain their cultural identity and they move to be an integral part of the other culture.

Separation: People value their own culture and wish to avoid interaction with other cultural groups.

Marginalisation: Little possibility or interest in one’s cultural maintenance and little interest in having relations with other cultural groups.

Multiple Choice

All learning that takes place without direct and deliberate teaching are known as:

• Acculturation

• Socialisation

• Enculturation

• Culture

Multiple Choice

  The key element of enculturation is learning by _________.

 

• Experiments

• Observation

• Case study

• None of these

Multiple Choice

During the British rule in India many individuals and groups adopted several aspects of British lifestyle. This change refers to

• Socialisation

• Enculturation

• Acculturation

• Culture

Multiple Choice

    An attitude in which there is little interest in one’s cultural maintenance and little interest in other cultural groups is termed as:

• Integration

• Assimilation

• Seperation

• Marginalisation