Chapter II : Heredity

Heredity

All human beings are more or less alike with each other in physical aspect. They vary considerably though in such factors as height, color of the skin, facial characteristics and intelligence. How can we seem to be alike but also be different at the same time? We all have the same body parts but we are also different with each other. We are unique in our own way because we have different genes that we inherited from our parents. You inherited your height from your father while the color of your hair was inherited from your mother. That’s why at the same time, the genes of your parents were transferred to you. The reason behind this was the heredity.

Why do children look like their parents? Why do brothers and sisters resemble each other? This is because we “inherit” traits from our parents. The passing of traits from parents to child is the basis of heredity. When we talk about heredity, the traits of one people can be relate to it easily. Our genes encode the instructions that define our traits. Each of us has thousands of genes, which are made of DNA and reside in our chromosomes. The environment we grow up and live in also helps define our traits. For example, while a person’s genes may specify a certain hair color, exposure to chemicals or sunlight can change that color.

Humans have two complete sets of twenty-three chromosomes,  meaning forty-six in total. These are threadlike structures that come in twenty-three pairs, one member of each pair comes from one parent. These are composed of DNA or Deoxyribonucleic Acid that is a complex molecule that contains genetic information. The units of hereditary information are short segments of chromosomes that compose the DNA that are known as genes. When parents conceive a child, they each contribute one complete set to the child. In this way, parents pass genes to the child.

Twenty-two pairs of chromosomes carry genes that determine the structures and behavior that are not sex-linked. The remaining pair of chromosomes called the sex chromosomes determine the sex of an individual. The sex chromosomes also carry genes determining other characteristics called sex-linked characteristics like baldness, colorblindness and hemophilia. By convention, the sex chromosomes are labelled x and y. Males have an x and a y sex chromosomes, females have two xx chromosomes.

The genes are the hereditary factors or “determiners” within the chromosomes. They are assumed to be “packets of chemicals” strung along the chromosomes like beads on a thread or peas in a pod.  Studies reveal that one constituent of genes, DNA has been tentatively identified as the primary genetic substance.

Genes work in pairs because the chromosomes inherited from the mother and the father pair up in such a way that pairs of similar genes determine particular characteristics. If a trait is determined by a single pair of identical genes, there is no doubt about the characteristics that will be produced.

The similarities between organisms of any kind are determined by heredity. Children are like their father or their mother or both. Yet, even if children are much like their parents, they may also have some of the characteristics of their grandparents. The reason behind this was because we inherit not only from our parents but from our ancestors as well.

Even if children look very much like their parents, we can still recognize one from each other. Each one of us tends to be different from our parents and from one another. No two individuals are exactly alike. Even identical twins differ from each other in certain ways. Some of these differences between organisms of the same specie are due to heredity, other are due to environment.

Every individual is a product of both heredity and environment. Man is a product of both nature and nurture – under the influence of these two factors he grows and changes biologically and psychologically. Heredity and environment in interacting with one another produce the whole range of individual differences.

Individuals differ from each other. Heredity and environment produce the whole range of individual differences among human beings. The internal environment is within an organism while the external environment which the stimuli is from the outside. It also includes our social environment composed of all human beings influencing us in any way or another. Our social environment is extremely important in shaping our individual especially our individual behavior and personality. 

Chapter I : Psychology as a Science

The writings of ancient Greek philosophers who did much speculation about the motivational aspects of human behavior , while the scientists of the Renaissance also made their own contributions by introducing the idea that observations could be further objectified through measurements, then the German psychologists and physicists of the nineteenth century used measurement techniques to study sensation and thus laid the foundation for scientific psychology. In primitive societies, man’s thinking about the phenomena of nature was restricted to uncritical traditions and superstitions.

The word psychology was derived from two Greek words, psyche (soul) and logos (discourse). Psychology or “mental philosophy was thus literally a study of soul. About four centuries ago, mental philosophers began o translate psyche as “mind” and psychology was then defined as “a study of mind”. It was eventually replaced by the definition of psychology as “ the science of behavior”.

Psychology is a science because it is systematic, empirical and dependent upon measurement. It is  is defined most simply as the scientific study of scientific 

thought or behavior.

Psychology is considered a science because it uses the scientific method in its analysis of human or animal behavior. The scientific method, in its simplest form, consists of several steps. The first step is asking a question. Psychologists ask questions regarding human behavior and try to get answers. The second step is doing background research. Psychologists have a wealth of background research available to them because of years of psychological research. The third step is to form a hypothesis. In psychology, there are many different hypotheses. Typically, psychology uses theoretical frameworks for forming a hypothesis. The fourth step the scientific method is to test the hypothesis using experiments. Psychologists have designed many different clever experiments to test the validity of different frameworks.An example of a theoretical framework for psychology is the birth order hypothesis for personality theory. Psychology encompasses a wide variety of brain sciences that use behavioral frameworks to predict behavior. In addition to personality theory, psychologists study personality and behavioral disorders such as obsessive compulsive disorder or schizophrenia using frameworks.The facts that psychologists are able to test the validity of their frameworks using the scientific method and psychologists are able to test their theories and try to modify them over time to fit new data is why psychology is considered a science.

Psychology is clearly a science because (1) It uses scientific method, almost all the methods of psychology are more or less scientific in their nature. Of these the experimental method is the most exact. (2) It is factual, psychology studies the facts of behaviour. (3) The laws of psychology are universal, the laws of psychology have been found to be correct in every time and place, under the same conditions. The general principles of human psychology are universal, whatever differences there may be in the psychology of different individuals. (4) The laws of psychology are veridical, thus by verification and reverification psychological principles have been found to be true everywhere. They can be verified by any one. (5) Psychology discovers the cause - effect relationship in human behavior. (6) Psychology predicts Human Behavior, by discovering the cause- effect relationship, psychology also predicts human behavior and these predictions are generally correct.

Psychology refers to the scientific study of behavior and mental processes. Behavior includes all of our outward or overt actions and reactions such as talking, facial expressions, and movements. Behavior and mental processes in animals and humans are studied using the scientific method so that their results will be as precise as possible. There are different types of behavior including, conscious and unconscious; rational and irrational; voluntary and involuntary; and covert and overt.

In a young and growing science, internal disputes often occur and psychology is not an exception. Psychologists have different ideas about what psychology should or should not include, about what it should emphasize and about what research methods are the best. When a large number of psychologists strongly support a certain view they are called a “school”. There are also schools of psychology namely, structuralism, functionalism, psychoanalysis, gestalt, cognitive, humanistic, existentialist and experimental.

The study of human behavior is a broad area and because of that, such varied material, several specialized subdivisions have developed. Like science, psychology have different branches as follows: general, physiological, comparative, genetic experimental developmental, personality, cognitive, abnormal, clinical, counselling, educational, social and industrial psychology.

Psychology also includes other sciences such as, physiology, history, sociology, and anthropology. It also involves indigenous methods: “pakapa-kapa”, “patanong-tanong”, “pagmamasid”, “pakikipanayam”, and “pagdalaw”.

Psychology as a science is of great importance to man because psychological problems are common to them.  Like any other sciences, it is a behavioral science. It is a scientific method applied to the study of behavior with the view of explaining why people act and behave the way they do. It enables the individual to learn more quickly and to chose a vocation more intelligently; enables a person to understand that no two individuals are alike; and also enables a person to resolve his own problems and to develop greater personal efficiency thus, the person develops himself into a well-integrated and happy individual.