Psychology Chapter 3 The Base Of Human Behaviour

Evolution refers to gradual and orderly biological changes that result in a species from their pre-existing forms in response to the changing adaptional demands of their environment. Physiological as well as behavioural changes that occur due to the evolution process are so slow that they become visible after hundreds of generations. Modern human beings possess some features for several thousand years. Three such important features which differentiate them from their ancestors are - (i) A bigger and developed brain with increased capacity for cognitive behaviours (ii) Ability to walk upright on two legs (iii) A free hand with a workable opposing thumb.

Our behaviours are highly complex and more developed than those of other species because we have got a large and highly developed brain. Human brain development is evidenced by two facts. Firstly, the weight of the brain is about 2.35 per cent of the total body weight, and it is the highest among all species. Secondly, the human cerebrum is more evolved than other parts of the brain. These evolutions have resulted due to the influence of environmental demands.

Some behaviours play an obvious role in evolution. For example, the ability to find food, avoid predators, and defend one’s young are the objectives related to the survival of the organisms as well as their species. The biological and behavioural qualities, which are helpful in meeting these objectives, increase an organism’s ability to pass it on to the future generation through its genes. The environmental demands lead to biological and behavioural changes over a long period of time.

Information is transmitted from one place to another within the nervous system in the form of a neural impulse. A single neuron can carry a neural impulse upto a distance covered by the length of its axon. When the impulse is to be conducted to a distant part of the body, a number of neurons participate in the process. In this process, one neuron relays the information to a neighbouring neuron. The axon tip of a preceding neuron make functional connections or synapse with dendrites of the other neuron.

Cerebral cortex has four lobes. These are (i) Frontal lobe, (ii) Parietal lobe, (iii) Temporal lobe, (iv) Occipital lobe.

(i) Frontal lobe: It is mainly concerned with cognitive functions, such as attention, thinking, memory, learning, and reasoning. It also exserts inhibitory effects on autonomous and emotional responses.

(ii) Parietal lobe: It is mainly concerned with cutaneous sensations and their co-ordination with visual and auditory sensations.

(iii) Temporal lobe: This is primarily concerned with the processing of auditory information. This is the site of memory for symbolic sounds and words. Understanding of speech and written language depends on this lobe.

(iv) Occipital lobe: It is mainly concerned with visual information. Interpretation of visual impulses, memory for visual stimuli and colour visual orientation is performed by this lobe.

The endocrine glands play a crucial role in our development and behaviour. Some of our behaviours are controlled by hormones secreted by different endocrine glands. The normal functioning of all hormones is crucial to our behavioural well-being. Without a balanced secretion of hormones, the body would be unable to maintain the state of internal equilibrium. Without the increased secretion of hormones during the times of stress, we would not be able to react effectively to potential dangers in our environment. Without the secretion of hormones at specific times in our lives, we would not be able to grow, mature and reproduce.

The autonomic nervous system governs activities which are normally not under direct control of individuals. The autonomic nervous system has two divisions - sympathetic division and parasympathetic division. The sympathetic division deals with emergencies when the action must be quick and powerful, such as in situations of fight or flight. During this period, the digestion stops, blood flows from internal organs to the muscles, and breathing rate, oxygen supply, heart rate.

The widely shared customs, beliefs, values, norms, institution and other products of a community that are transmitted socially across generation.

Important features of culture:

1. Culture contains values that will be expressed and language in which to express them.

2. Culture is identified with historically transmitted pattern of meaning embodied in symbols.

Yes, biology plays an enabling role, while specific aspects of behaviour are related to cultural factors. Many of our behaviours are influenced by hormones and many others occur as reflexive responses. However, hormones and reflexes do not explain all of our behaviour. Human behaviour is more complex than the behaviour of animals. A major reason for this complexity is that unlike animals human beings have a culture to regulate their behaviour. It can be explained by an example.

Sexual behaviour involves hormones and reflexive reactions in animals and human beings alike. While among animals sexual behaviour is fairly simple and reflexive, it is so complex among human beings that it can hardly be described as reflexive partner preferences or a key feature of human sexual behaviour. The bases of these preference widely differ within and across societies. Human sexual behaviour is also governed by many rules, standards, values and laws. However, these rules and standards also remain in a continuous, process of change.

Thus, it is established that biological factors alone cannot help us very much in understanding human behaviour. Human nature has evolved through an interplay of biological and cultural forces.

A number of people who relate to us possess power to socialise us. Such people are called socialisation agents. Some of the main agents of socialisation are as follows:

(i) Parents: They have most direct and significant impact on children’s development. Children respond in different ways to parents in different situations. Parents encourage certain behaviours by rewarding them verbally (e.g., praising) or in other tangible ways (e.g., buying chocolates or objects of child’s desire). They also discourage certain behaviours through non-approving behaviours. They also arrange to put children in a variety of situations that provide them with a variety of positive experiences, learning opportunities, and challenges. The conditions of life in which parents live (such as poverty, job stress, illness, nature of family) also influence the styles they adopt in socialising children. Grand parental proximity and network of social relationships play considerable role in child socialisation directly or through parental influences.

(ii) School: School is another important socialising agent. Children learn many cognitive skills (such as reading,writing), and social skills (such as ways of behaving with elders and age males, accepting roles, fulfilling responsibilities). They also learn and internalise the norms and rules of society. Several other positive qualities, such as self-initiative, self-control, responsibility, land creativity are encouraged in schools. These qualities make children more self-reliant. A good school can altogether transform a child’s personality.

(iii) Peer groups: Friendship provides children good opportunity to be in company of others. It also provides organising various activities (e.g., play) collectively with the members of their own age. Qualities like sharing, trust, mutual understanding, role acceptance and fulfilment develop in interaction with peers. Children also learn to assert their own point of view and accept and adopt to those of others. Development of self identity is greatly facilitated by the peer group. Since communication of children with peer group is direct, process of socialisation is generally smooth.

(iv) Media influences: Today media has become a very influencial agent of socialisation. Children learn about many things from different means of media (such as television, newspapers, cinema). Adolescents and young adults often derive their models from them, particularly from television and cinema. However, there is also a negative aspect. Observing violence on television enhances aggressive behaviour among children. Thus, there is a need to use this agent of socialisation in a better way in order to prevent children from developing undesirable behaviours.

Enculturation: It refers to all learning that takes place without direct, deliberate teaching. It refers to all learning that occurs in human life because of its availability in our socio-cultural context. Observation is the key element of enculturation in learning. Whenever we learn any content of our society by observation, enculturation is in evidence. These contents are culturally shaped by our preceding generations. A major part of our behaviour is the product of enculturation.

Socialisation: It is a process by which individuals acquire knowledge, skills and dispositions, which enable them to participate as effective members of groups and society. It is a process that continues over the entire life-span, and through which one learns and develops ways of effective functioning at any stage of development. Socialisation forms the basis of social and cultural transmission from one generation to the next. Its failure in any society may endanger the very existence of that society.

Acculturation refers to cultural and psychological changes resulting from contact with other cultures. Contact may be direct (e.g., when one moves and settles in a new culture) or indirect (e.g., through media or other means. It may be voluntary (e.g., when one goes abroad for higher studies, training, job or trade) or involuntary (e.g., through colonial experience, invasion, political refuge). In both cases, people often need to learn something new to negotiate with people of other cultural groups.

Acculturation can take place any time in one’s life. Whenever it occurs, it requires re-learning of norms, values, dispositions, and patterns of behaviour. Changes in these aspects require re-socialisation. Sometimes people find it easy to learn these new things, and if their learning has been successful, shifts in their behaviour easily take place in the direction of the group that brings in acculturation. In this situation transition to a new life is relatively smooth and free from problems.

Following are the acculturative strategies adopted by individuals during the course of acculturation:

(i) Integration: It refers to an attitude in which there is an interest in both, maintaining one’s original culture and identity, while staying in daily interaction with other cultural groups.

(ii) Assimilation: It refers to an attitude, which people do not wish to maintain their cultural identity, and they move to become an integral part of the other culture. In this case, there is loss of one’s culture and identity.

(iii) Separation: It refers to an attitude in which people seem to place a value on holding on to their original culture, and wish to avoid interaction with other cultural groups. In this case, people often tend to glorify their cultural identity.

(iv) Marginalisation: It refers to an attitude in which there is little possibility or interest in one’s cultural maintenance and little interest in having relations with other cultural groups. In this case, people generally remain undecided about what they should do and continue to stay with a great deal of stress.

Evolution refers to gradual and orderly biological changes.

Physiological and behavioural changes occur due to evolution.

Evolution occurs through the process of natural selection.

The weight of the brain is about 2.35 per cent of the total body weight.

Cerebrum.

Neuron is the basic unit of our nervous system.

Neurons are specialised cells, which possess the unique property of converting various forms of stimuli into electrical impulses.

Nearly 12 billion neurous are found in the human nervous system.

The common fundamental components of different neurons are soma, dendrites, and axon.

The soma is the main body of the nerve cell.

Inside nucleus.

Their function is to receive the incoming neural impulses from adjacent neurons or directly from the sense organs.

Sensory nerves carry information from sense organs to central nervous system.

The full form of PNS is Peripheral nervous system, ANS is Autononous nervous system and RNA is Ribonuclei acid.

Motor nerves carry information from central nervous system to muscles or glands.

Synaptical cleft.

The conduction of neural impulse in the axon is electrochemical.

Brain and spinal cord.

Eyes, ears, and skin.

Sensory nerves collect information from receptors of the head region (vision, audition, smell, taste, touch, etc.) and carry them to the brain.

The motor nerves carry motor impulses originating from the brain to muslces of the head region.

The digestion stops, blood flows from internal organs to the muscles, and breathing rate, oxygen supply, heart-rate, and blood sugar level increases.

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

The parasympathetic division is mainly concerned with conservation of energy. It monitors the routine functions of the internal system of the body.

Cerebral cortex.

An adult brain weight about 1.36 kg.

The Occipital lobe.

It regulates basic life supporting activities like breathing, heart rate, and blood pressure.

The ‘pons’ is involved in sleep mechanism, particularly the sleep characterised by dreaming.

The main function of cerebellum is coordination of muscular movements.

Hypothalamus regulates physiological processes involved in emotional and motivational behaviour, such as eating, drinking, sleeping, temperature regulation and sexual arousal.

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

Eye-blinking, knee jerk, pupil constriction, pulling away from very hot or cold objects, breathing and stretching.

Pituitary gland.

Insulin.

Gonads refer to testes in males and ovaries in females.

GTH: Gonadotrophic hormone.

Progesterone’s function is related with preparation of uterus for the possible reception of fertilized ovum.

Androgens are male sex hormones.

Testesterone.

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

23 chromosomes.

46 chromosomes (23 pairs)

The observable traits of an organism are called phenotypes. Examples — body built, physical strength, intelligence.

Change of a gene from one form to another is called mutation.

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

The key element of enculturation is learning by observation.

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

A number of people who relate to us possess power to socialise us. Such people are called “socialisation agents”.

Parents, family members, school, and media.

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

Integration, assimilation, separation, and marginalisation.

Marginalisation refers to an attitude in which there is little possibility or interest in one’s cultural maintenance, and little interest in having relations with other cultural groups.

It is highly developed part of the brain. it is easily recognized by its wrinkle surface. It maintain and controls the posture and equilibrium of body.

Three main parts of forebrain are as follows:

(a) Hypothalamus, (b) Thalamus, (c) The limbic system.

The cerebrum is divided in two symmetrical halves. Although two hemispheres appear identi-cal, functionally one hemisphere dominates other.

The two hemispheres of cerebrum are connected by myleneated fibre called corpus colloscum.

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

(i) A bigger and developed brain with increased capacity for cognitive behaviours like perception, memory, reasoning, problem solving, and use of language for communication.

(ii) Ability to walk upright on two legs.

(iii) A free hand with a workable opposing thumb.

Cranial nerves are the nerves of the somatic nervous system. There are twelve sets of cranial nerves which either emanate from or reach different locations of the brain. There are three types of cranial nerves-sensory, motor, and mixed. Sensory nerves collect sensory information from receptors of the head region (vision, audition, smell, taste, touch etc.) and carry them to the brain. The motor nerves carry motor impulses originating from the brain to muscles of the head region. For example, movements of the eyeballs are controlled by motor cranial nerves. Mixed nerves have both sensory and motor fibres, which conduct sensory and motor information to and from the brain.

Spinal nerves are nerves of somatic nervous system. There are thirty-one sets of spinal nerves coming out of or reaching to the spinal cord. Each set has sensory and motor nerves. Spinal nerves have two functions. The sensory fibres of the spinal nerves collect sensory information from all over the body except the head region and send them to the spinal cord from where they are then carried out to the brain. Also, motor impulses coming down from the brain are sent to the muscles by the motor fibres of the spinal nerves.

I. Hind brain: This part of the brain consists of following structure :

(a) Medulla oblonganta: It consist of lowest part of the brain that exist in continuation of spinal cord.

(b) Pons: It is connected with medulla on one side with the midbrain on the other. It is involved in sleep mechanism.

(c) Cerebellum: This is highly developed part of the hind brain.

II. Midbrain: The midbrain is relatively small in size and it connects the hind brain with the forebrain.

III. Forebrain: It is most important part of the brain because it perform all cognitive, emotional and motor activities.

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 an anterior pituitary hormone, the Thyroid Stimulating Hormone, (TSH). The steady secretion of this hormone maintains the production of energy consumption of oxygen and elimination of wastes in body cells. Underproduction of thyroxin leads to physical and psychological lethargy. If thyroid gland is removed in young animals, their growth is stunted and they fail to develop sexually.

Gonads refer to ovaries in females. The ovaries in females produce estrogens and progesterone. Estrogens guide the sexual development of the female body. Primary sexual characteristics related with reproduction, such as development of ovum, appear on every 28 days or so in the ovary of a sexually matured female. Secondary sexual characteristics, such as breast development, round body contours, widened pelvis, etc. also depend on this hormone. Progesterone has no role in sexual development. Its function is to prepare uterus for the possible reception of fertilized ovum.

The gene comes in pairs. Both genes in the pair may be dominant or one may be dominant and the other recessive. The dominant gene is responsible for a particular trait act seen in a person. The characteristics which we see (such as eye, colour etc.) are called phenotypes. The recessive gene does not show up as a trait, unless paired with another gene just like it. The characteristics that are passed on genetically (as recessive genes) but are not displayed are called genotypes.

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

Media play very important role as a socialisation agent. Through television, newspapers, books and cinema, the external world has made or in making its way into our homes and our lives. Children learn about many things from these sources. Adolescents and young adults often derive their models from them, particularly from television and cinema. These days, exposure to violence on television is a major issue, since it is studied that observing violence on television enhances aggressive behaviour among children. So there is a need to use this agent of socialisation in a better way in order to prevent children from developing undesirable behaviours.

It refers to the attitude in which there is little possibility or interest in one cultural maintainence and little interest in having relation with other cultural groups. People generally remain undecided about what they should do.

Structurally the brain can be divided into three parts–hind-brain, mid-brain and forebrain.

(i) Hind brain: This part of the brain consists of the following structure :

(a) Medula Oblongata: 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. The medula is known as the vital centre of the brain.

(b) Pons: It is connected with medulla on one side and with the midbrain on the other. It is involved in sleep mechanism, particularly the sleep characterised by dreaming. It contains nuclei affecting respiratory movement and facil expressions also.

(c) Cerebellum: It maintains and controls posture and equilibrium of the body. It’s main functions is co-ordination of muscular movement.

(ii) Mid brain: It is relatively small in size and it connects the hind-brain with the fore-brain. This part of the brain is responsible for our arousal. It makes us alert and active by regulating sensory inputs. It also helps us in selecting information from the environment.

(iii) Fore-brain: This is the most important part of the brain as it performs all cognitive, emotional, and motor activities. It consists of the following structures:

(a) Hypothalamus: It plays vital role in our behaviour. It regulates physiological processes involved in emotional and motivational behaviour, such as eating, drinking, sleeping, temperature regulation, and sexual arousal. It also regulates and controls the internal environment of the body (e.g. heart rate, blood pressure, temperature) and regulates the secretion of hormones from various endocrine glands.

(b) Thalamus: It receives all incoming sensory signals from sense organs and sends them to appropriate parts of the cortex for processing. It also receives all outgoing motor signals coming from the cortex and sends them to appropriate parts of the body.

(c) The Limbic system: It helps in maintaining internal homeostasis by regulating body temperature, blood pressure, and blood sugar level.

(d) The Cerebrum: This part of the brain regulates all higher levels of cognitive functions, such as attention, perception, learning, memory, language behaviour, reasoning, and problem solving. The cerebrum makes two-third of the total mass of the human brain. Its thickness varies from 1.5 mm to 4 mm. which covers the entire surface of the brain and contains neurons, neural nets, and bundles of axons. All these make it possible for us to perform organised actions and create images, symbols, associations and memories.

A.

slow

C.

2.35

B.

Soma

D.

electrochemical

A.

synaptic cleft

A.

dilates pupil

C.

It decreases digestive functions of stomach

D.

Pons

B.

Hypothalamus

C.

The frontal lobe of cerebrum

D.

All of the above

C.

Pituitary gland

A.

Pancreas

C.

Insulin

C.

Estrogens

B.

zygote cell

D.

23

B.

Enculturation

D.

All of the above

B.

Socialisation

A.

Acculturation

C.

Marginalisation