Basic Issues In Human Development PDF

Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm BASIC ISSUES IN HUMAN DEVELOPMENT There are basic issues in understanding development. 1. Assumptions about Human Nature a) Original Sin: Thomas Hobbes portra...

Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm BASIC ISSUES IN HUMAN DEVELOPMENT There are basic issues in understanding development. 1. Assumptions about Human Nature a) Original Sin: Thomas Hobbes portrayed children as inherently selfish and bad, believing that it was society‟s task to control their selfish and aggressive impulses and to teach them to behave in positive ways. b) Inherently Good: Jean Jacques Rousseau argued that children were innately good, that they were born with an intuitive understanding of right and wrong, and that they would develop in positive directions as long as society did not interfere with their natural tendencies. c) Tabula Rasa: John Locke maintained that an infant is a tabula rasa, or a blank slate waiting to be written on by his or her own experiences. Locke believed that children were neither innately good nor bad; they could develop in any number of directions depending on their own experiences. 2. Nature and Nurture One of the prevailing issues in psychology is the age-old debate on nature and nurture, continuously seeking to understand the influence of nature (heredity) and nurture (environment) on human development. The debate intends to find out whether genetic factors have more influence on one’s behavior or personality over environmental factors or the other way around. Nature refers to the behavior and characteristics manifested because of the influence of biological forces (heredity and biologically based dispositions). Nurture refers to the influences brought about by exposure to the environment (includes learning experiences, child-rearing methods, societal changes, and culture; in other words, it pertains to the totality of non-hereditary or experiential influences on development). Heredity, Environment and Maturation Some influences on development originate primarily with heredity – inborn traits or characteristics inherited from the biological parents. Other influences come largely from the environment – the totality of nonhereditary or experiential influences on development. Which of these factors has more impact on development? Nature vs Nurture historically generated intense debate. Contemporary theorists and researchers are more interested in finding ways to explain how nature and nurture work together than in arguing about which factor is more important. To get a callus, you have to have callus-making genes of some sort, but the environmental input of repeated friction on your skin is also required or a callus would never form. Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm Many typical changes of infancy and early childhood, such as the abilities to walk and talk, are tied to maturation (unfolding of a natural sequence of physical and behavioral changes) of the body and brain. Only when deviation from the average is extreme should we consider development exceptionally advanced or delayed. To understand development, we need to look at the inherited characteristics that give each person a start in life. We also need to consider the many environmental factors that affect development such as family, neighborhood, socioeconomic status, race/ethnicity, and culture. We need to understand which developments are primarily maturational and which are not; which influences affect many or most people at a certain age and how timing can accentuate the impact of certain influences. 3. Is development active or reactive? Psychologists who believe in reactive development conceptualize the developing child as a hungry sponge that soaks up experiences and is shaped by this input over time. Psychologists who believe in active development argue that people create experiences for themselves and are motivated to learn about the world around them. Reactive – children grasp experiences and this input molds them over time. Active – people create experiences and are motivated to learn about the world around them. 4. Is development continuous or discontinuous? Continuous – development is gradual and incremental. Continuity theorists view human development as a process that occurs in small steps, without sudden changes. Discontinuous – development is abrupt or uneven; stages. Discontinuity theorists picture the course of development as more like a series of stair steps, each of which elevates the individual to a new (and presumably more advance) level of functioning. Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm Quantitative changes are changes in degree and indicate continuity; changes in height, weight: a person becomes taller, knows more vocabulary words, or interacts with friends more or less frequently). Qualitative changes are changes in kind and suggest discontinuity – changes that make the individual fundamentally different in some way than he or she was before, changes in structure, or organization, not just in number but in the way that children think, behave, and perceive the world as they mature (a nonverbal infant into a speaking toddler). 5. Universality and Context-specificity This pertains to the extent to which developmental changes are common to everyone (universal) or different from person to person (context-specific). Life Span Development – now considered by researchers to be from “womb” to “tomb”; comprising the entire human life span from conception to death. Development can be either positive or negative: Positive: becoming toilet trained or enrolling in a college course after retirement. Negative: once again wetting the bed after a traumatic event or isolating yourself after retirement. Goals of human development: 1) Description – describe when most children say their first word or how large their vocabulary is at a certain age by observing large groups of children and establish norms or averages, for behavior at various ages. 2) Explanation – explain how children acquire language and why some children learn to speak later than usual. 3) Prediction – predict the likelihood that a child may have serious speech problems.‟ 4) Intervention – intervene in development by giving a child speech therapy. The Life Span Perspectives There are seven assumptions of the breadth and depth of development as discussed by Paul Baltes: 1) Development is a lifelong process. We continue developing new understandings of our environment and the world around us. 2) Development is multidirectional. Development in one area is simultaneous with other areas. While children are learning to walk, their socialization skills is also enhanced. 3) Development always involves both gain and loss. Development at every age involves both growth and decline. For example, gaining a capacity for logical thought as a Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm school-age child may mean losing some capacity for the fanciful and imaginative thinking of a pre-schooler. 4) Development is characterized by lifelong plasticity. Plasticity refers to the capacity to change in response to positive or negative experiences. 5) Development is shaped by its historical/cultural context. A person‟s development is affected by the culture and the history of the society he or she grew up in. An example of this is observed in the types of careers students in a particular community pursue. 6) Development is influenced by multiple factors. It is the product of on-going interactions between a changing person and his or her changing world. 7) Understanding development requires multiple disciplines. It is best understood by having knowledge of the psychological perspectives, biological underpinning and sociological context. PERIODS OF THE LIFE SPAN Division of the life span into periods is a social construction. Social construction – a concept or practice that may appear natural and obvious to those who accept it, but that in reality is an invention of a particular culture or society. Childhood is in varied forms across cultures: US: children have relative freedom. Children in colonial times do adult-like tasks such as knitting socks and spinning wool. Inuit parents in the Canadian Arctic believe that young children are not yet capable of thought and reason so they are lenient when children cry or become angry. Parents on the Pacific Island of Tonga regularly beat 3-5-year-olds because crying is attributed to willfulness. Ø Prenatal Period – conception to birth. Conception signals the beginning of prenatal development which starts with fertilization in the germinal stage through the implantation in the embryonic development and continues through cell differentiation in fetal development. The average duration for prenatal development to complete is 38 weeks from the date of conception. Ø Infancy and toddlerhood After birth, dramatic growth and changes occur during the first 18 to 24 months wherein a newborn, equipped with several involuntary reflexes and an initially strong sense of audition (hearing) but poor vision (sight), is transformed into an actively walking and talking toddler. Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm Ø Early childhood (ages 3 to 6) Early childhood is often referred to as preschool age. While the child is actively developing his or her fine (use of small muscles) and gross (use of large muscles) motor skills, he or she gains remarkable growth in vocabulary and cognitive development and dramatically acquires language (first and second) and gains a sense of self and greater independence. Ø Middle Childhood (ages 6 to 11) This is the grade school age. Physical growth slows down and while the child’s world becomes one of acquiring academic skills, the children are able to refine their motor skills, acquire foundational skills for building healthy social relationships beyond the family and learn roles that will prepare them for adolescence and adulthood. It is the time for children to show off their accomplishments in school in varied areas. Ø Adolescence (ages 11 to about 20) Adolescence is a period of development with specific health and developmental needs and rights. It is also a time to develop knowledge and skills, learn to manage emotions and relationships, and acquire attributes and abilities that will be valuable for experiencing the adolescent years and later assuming adult responsibilities. Adulthood (Early, Middle, and Late) Ø Emerging and Young Adulthood (ages 20 to 40) While physical maturation is done, physiological capabilities such as sensory abilities, reaction time, muscle strength, and even cardiac functioning are at their peak. Foremost tasks of the stage include establishing identity, developing more stable emotional stability, establishing a career, forming intimate and long-term relationships, becoming involved with various groups in the community, establishing a residence, adjusting to marital relationships, and learning how to be a parent. Ø Middle Adulthood (ages 40 to 65) Slow deterioration of sensory abilities, health, stamina, and strength may begin, but individual differences are wide. Women experience menopause. Ø Late adulthood (age 65 and over) Retirement from the workforce may occur and may offer new options for use of time. People develop more flexible strategies to cope with personal losses and impending death. Relationships with family and close friends can provide important support. Search for meaning in life assumes central importance. Developmental Theories and Other Relevant Theories Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm FREUD’S PSYCHOSEXUAL STAGES OF DEVELOPMENT SIGMUND FREUD Sigmund Freud (1856-1939) was a Viennese doctor who came to believe that the way parents dealt with children's basic sexual and aggressive desires would determine how their personalities developed and whether or not they would end up well-adjusted as adults. Freud described children as going through multiple stages of sexual development, which he labeled Oral, Anal, Phallic, Latency, and Genital. The Role of Conflict Each of the psychosexual stages is associated with a particular conflict that must be resolved before the individual can successfully advance to the next stage. The resolution of each of these conflicts requires the expenditure of sexual energy and the more energy that is expended at a particular stage, the more important characteristics of that stage remain with the individual as he/she matures psychologically. To explain this Freud suggested the analogy of military troops on the march. As the troops advance, they are met by opposition or conflict. If they are highly successful in winning the battle (resolving the conflict), then most of the troops (libido) will be able to move on to the next battle (stage). But the greater the difficulty encountered at any particular point, the greater the need for troops to remain behind to fight and thus the fewer that will be able to go on to the next confrontation. Frustration, Overindulgence, and Fixation Some people do not seem to be able to leave one stage and proceed on to the next. One reason for this may be that the needs of the developing individual at any particular stage may not have been adequately met in which case there is frustration. Or possibly the person's needs may have been so well satisfied that he/she is reluctant to leave the psychological benefits of a particular stage in which there is overindulgence. Both frustration and overindulgence (or any combination of the two) may lead to what psychoanalysts call fixation at a particular psychosexual stage. Fixation refers to the theoretical notion that a portion of the individual's libido has been permanently 'invested' in a particular stage of his development. Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm Oral Stage (Birth to 1 year) In the first stage of personality development, the libido is centered in a baby's mouth. It gets much satisfaction from putting all sorts of things in its mouth to satisfy the libido, and thus its id demands. Which at this stage in life are oral, or mouth orientated, such as sucking, biting, and breastfeeding. Freud said oral stimulation could lead to an oral fixation in later life. We see oral personalities all around us such as smokers, nail-biters, finger-chewers, and thumb-suckers. Oral personalities engage in such oral behaviors, particularly when under stress. Anal Stage (1 to 3 years) The libido now becomes focused on the anus, and the child derives great pleasure from defecating. The child is now fully aware that they are a person in their own right and that their wishes can bring them into conflict with the demands of the outside world (i.e., their ego has developed). Freud believed that this type of conflict tends to come to a head in potty training, in which adults impose restrictions on when and where the child can defecate. The nature of this first conflict with authority can determine the child's future relationship with all forms of authority. Early or harsh potty training can lead to the child becoming an anal-retentive personality who hates mess, is obsessively tidy, punctual, and respectful of authority. They can be stubborn and tight-fisted with their cash and possessions. This is all related to the pleasure got from holding on to their feces when toddlers and their mum's then insist that they get rid of it by placing them on the potty until they perform! Not as daft as it sounds. The anal expulsive, on the other hand, underwent a liberal toilet-training regime during the anal stage. In adulthood, the anal expulsive is the person who wants to share things with you. They like giving things away. In essence, they are 'sharing their s**t'!' An anal-expulsive personality is also messy, disorganized, and rebellious. Phallic Stage (3 to 6 years) Sensitivity now becomes concentrated in the genitals and masturbation (in both sexes) becomes a new source of pleasure. The child becomes aware of anatomical sex differences, which sets in motion the conflict between erotic attraction, resentment, rivalry, jealousy, and fear which Freud called the Oedipus complex (in boys) and the Electra complex (in girls). This is resolved through the process of identification, which involves the child adopting the characteristics of the same-sex parent. Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm The most important aspect of the phallic stage is the Oedipus complex. This is one of Freud's most controversial ideas and one that many people reject outright. The name of the Oedipus complex derives from the Greek myth where Oedipus, a young man, kills his father and marries his mother. Upon discovering this, he pokes his eyes out and becomes blind. This Oedipal is the generic (i.e., general) term for both Oedipus and Electra complexes. In the young boy, the Oedipus complex or more correctly, conflict, arises because the boy develops sexual (pleasurable) desires for his mother. He wants to possess his mother exclusively and get rid of his father to enable him to do so. Irrationally, the boy thinks that if his father were to find out about all this, his father would take away what he loves the most. During the phallic stage what the boy loves most is his penis. Hence the boy develops castration anxiety. The little boy then sets out to resolve this problem by imitating, copying, and joining in masculine dad-type behaviors. This is called identification and is how the three-to- five-year-old boy resolves his Oedipus complex. Identification means internally adopting the values, attitudes, and behaviors of another person. The consequence of this is that the boy takes on the male gender role, and adopts an ego ideal and values that become the superego. For girls, the Oedipus or Electra complex is less than satisfactory. Briefly, the girl desires the father but realizes that she does not have a penis. This leads to the development of penis envy and the wish to be a boy. The girl resolves this by repressing her desire for her father and substituting the wish for a penis with the wish for a baby. The girl blames her mother for her 'castrated state,' and this creates great tension. The girl then represses her feelings (to remove the tension) and identifies with the mother to take on the female gender role. Latency Stage (6 years to puberty) No further psychosexual development takes place during this stage (latent means hidden). The libido is dormant. Freud thought that most sexual impulses are repressed during the latent stage, and sexual energy can be sublimated (re: defense mechanisms) towards school work, hobbies, and friendships. Much of the child's energy is channeled into developing new skills and acquiring new knowledge, and play becomes largely confined to other children of the same gender. Genital Stage (puberty to adult) This is the last stage of Freud's psychosexual theory of personality development and begins in puberty. It is a time of adolescent sexual experimentation, the successful Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm resolution of which is settling down in a loving one-to-one relationship with another person in our 20s. Sexual instinct is directed to heterosexual pleasure, rather than self-pleasure like during the phallic stage. For Freud, the proper outlet of the sexual instinct in adults was through heterosexual intercourse. Fixation and conflict may prevent this with the consequence that sexual perversions may develop. For example, fixation at the oral stage may result in a person gaining sexual pleasure primarily from kissing and oral sex, rather than sexual intercourse. Tripartite Theory of Personality Freud (1923) saw the personality structured into three parts (i.e., tripartite), the id, ego, and superego (also known as the psyche), all developing at different stages in our lives. These are systems, not parts of the brain, or in any way physical. The id is the primitive and instinctive component of personality. It consists of all the inherited (i.e., biological) components of personality, including the sex (life) instinct – Eros (which contains the libido), and aggressive (death) instinct - Thanatos. It operates on the pleasure principle (Freud, 1920) which is the idea that every wishful impulse should be satisfied immediately, regardless of the consequences. The ego develops in order to mediate between the unrealistic id and the external real world (like a referee). It is the decision-making component of personality The ego operates according to the reality principle, working our realistic ways of satisfying the id‘s demands, often compromising or postponing satisfaction to avoid negative consequences of society. The ego considers social realities and norms, etiquette, and rules in deciding how to behave. The superego incorporates the values and morals of society which are learned from one's parents and others. It is similar to a conscience, which can punish the ego by causing feelings of guilt. Erik Erikson’s Psycho-Social Theory of Development Erik Homburger Erikson 8 Stages of Psychosocial Development Best-known theories of personality and development. Personality develops in a series of predetermined stages. Psychosocial, and not psychosexual. In each stage of development, conflicts act as turning points in life Personality- consists of all the relatively stable and distinctive styles of thought, behavior, and emotional responses that characterize a person‘s adaptations to surrounding situations. Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm Psychosexual Development- Refers to the emotional and psychological changes across the life cycle that occur in the context of the individual‘s social environment. 1. Trust vs. Mistrust Trust vs. mistrust is the first stage in Erik Erikson's theory of psychosocial development. This stage begins at birth and continues until approximately 18 months of age. During this stage, the infant is uncertain about the world in which they live and looks towards their primary caregiver for stability and consistency of care. 2. Autonomy vs. Shame and Doubt Autonomy versus shame and doubt is the second stage of Erik Erikson's stages of psychosocial development. This stage occurs between the ages of 18 months to approximately 3 years. According to Erikson, children at this stage are focused on developing a sense of personal control over physical skills and a sense of independence. 3. Initiative vs. Guilt Initiative versus guilt is the third stage of Erik Erikson's theory of psychosocial development. During the initiative versus guilt stage, children assert themselves more frequently. These are particularly lively, rapid-developing years in a child‘s life. According to Bee (1992), it is a ―time of vigor of action and of behaviors that the parents may see as aggressive." 4. Industry vs. Inferiority Erikson's fourth psychosocial crisis, involving industry (competence) vs. inferiority occurs during childhood between the ages of five and twelve. Children are at the stage where they will be learning to read and write, to do sums, to do things on their own. Teachers begin to take an important role in the child‘s life as they teach the child specific skills. 5. Identity vs. Role Confusion The fifth stage of Erik Erikson's theory of psychosocial development is identity vs. role confusion, and it occurs during adolescence, from about 12-18 years. During this stage, adolescents search for a sense of self and personal identity, through an intense exploration of personal values, beliefs, and goals. 6. Intimacy vs. Isolation Intimacy versus isolation is the sixth stage of Erik Erikson's theory of psychosocial development. This stage takes place during young adulthood between the ages of approximately 18 to 40 yrs. During this period, the major conflict centers on forming intimate, loving relationships with other people. 7. Generativity vs. Stagnation Generativity versus stagnation is the seventh of eight stages of Erik Erikson's theory of psychosocial development. This stage takes place during during middle adulthood (ages 40 to 65 yrs). Generativity refers to "making your mark" on the world through creating or nurturing things that will outlast an individual Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm 8. Ego Integrity vs. Despair Ego integrity versus despair is the eighth and final stage of Erik Erikson‘s stage theory of psychosocial development. This stage begins at approximately age 65 and ends at death. It is during this time that we contemplate our accomplishments and can develop integrity if we see ourselves as leading a successful life. Social Learning Theory by Albert Bandura The psychologist Albert Bandura (1925-2021) developed many of the principles of social learning theory. Whereas behaviorists see the environment as the chief impetus for development, Bandura (1989) suggested the impetus for development is bidirectional. Bandura called this concept reciprocal determinism: The person acts on the world as the world acts on the person. Classic social learning theory maintains that people learn appropriate social behavior chiefly by observing and imitating models; that is, by watching other people. This process is called observational learning, or modeling. For example, Clara sees her sister get disciplined for eating a cookie cooling on the counter and thus restrains herself from doing the same thing without herself getting punished. Bandura’s updated version of social learning theory is social cognitive theory. The change of name reflects a greater emphasis on cognitive processes as central to development. Cognitive processes are at work as people observe models, learn chunks of behavior, and mentally put the chunks together into complex new behavior patterns. Rita, for example, imitates the toes-out walk of her dance teacher but models her dance steps after those of Lucy, a slightly more advanced student. Even so, she develops her own style of dancing by putting her observations together into a new pattern. Through feedback on their behavior, children gradually form standards for judging their actions and become more selective in choosing models who demonstrate those standards. They also begin to develop a sense of self-efficacy, or confidence in their abilities. Piaget’s Stages of Cognitive Development Schema- Piaget used the term ―schema‖ to refer to the cognitive structure by which individuals intellectually adapt to and organize their environment. It is an individual‘s way of understanding or creating meaning about a thing or experience. Assimilation- cognitive structure by which individuals intellectually adapt to and organize their environment. It is an individual‘s way of understanding or creating meaning about a thing or experience. Equilibration- Equilibration is achieving a proper balance between assimilation and accommodation. When our experiences do not match our schemata (plural of schema) cognitive structures, we experience cognitive disequilibrium this means there is a discrepancy between what is perceived and what is understood. We then exert effort through assimilation and accommodation to establish an equilibrium Stage 1. Sensorimotor Stage The first stage corresponds to infancy. This is the stage when a child who is initially reflexive in grasping, sucking, and reaching becomes more organized in his movement and activity. The term sensorimotor focuses on the prominence of the senses and muscle movement through which the infant comes to learn, about him and the world. Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm Object permanence This is the ability of the child to know that an object still exists even when out of sight. This ability is attained in the sensory-motor stage. Stage 2. Pre-operational Stage The preoperational stage covers from about two to seven years old roughly corresponding to the preschool years. Intelligence at this stage is intuitive in nature. At this stage, the child can now make mental representations and is able to pretend the child is now ever closer to the use of symbols. This stage is highlighted by the following: Stage 3. Concrete- Operational Stage This stage is characterized by the ability of the child to think logically but only in terms of concrete objects. This covers approximately the ages between 8 - 11 years or the elementary school years. Stage 4. Formal Operational Stage In the final stage of formal operations covering ages between 12 and 15 years, thinking becomes more logical. They can now solve in general ideas or specific problems and an educated guesses. Sociocultural theory of development: The crucial influence that social interactions and language, embedded within a cultural context, have on cognitive development. Vygotsky emphasized that effective learning happens through participation in social activities. Parents, teachers, and other adults in the learner‘s environment all contribute to the process. They explain, model, assist, give directions, and provide feedback. Peers, on the other hand, cooperate and collaborate and enrich the learning experience. Language Language can be viewed as a verbal expression of culture. Every culture has the words it needs for its lifestyle. It opens the door for learners to acquire knowledge that others already have. It is used to know and understand the world and solve problems. It serves a social function but it also has an important individual function. It helps the learner to regulate and reflect on his own thinking. Zone of Proximal Development Zone of Actual Development - The child may perform a certain level of competency she/ he may not immediately be at it. Zone of Proximal Development - The difference between what the child accomplishes alone and what he/she can accomplish with the guidance of another. Scaffolding - Refers to the support or assistance that lets the child accomplish a task he/she cannot accomplish independently. Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm It is not about doing the task for the child while he/she watches. It is not about doing shortcuts for the child It should involve the judicious assistance given by the adult or peer so that the child can move from the zone of actual to the zone of proximal development. The Bioecological Theory American psychologist, Urie Bronfenbrenner, formulated the Ecological Systems Theory to explain how the inherent qualities of children and their environments interact to influence how they grow and develop. The Bronfenbrenner theory emphasizes the importance of studying children in multiple environments, also known as ecological systems, in an attempt to understand their development. According to Bronfenbrenner‘s Ecological Systems Theory, children typically find themselves enmeshed in various ecosystems, from the most intimate home ecological system to the larger school system, and then to the most expansive system which includes society and culture. Each of these ecological systems inevitably interacts with and influences each other in all aspects of the children‘s lives. Research Methods Quantitative Methods emphasize objective measurements and the statistical, mathematical, or numerical analysis of data collected through polls, questionnaires, and surveys, or by operating pre-existing statistical data using computational techniques. Quantitative research focuses on gathering numerical data and generalizing it across groups of people or to explain a particular phenomenon. Qualitative Methods. The word qualitative implies an emphasis on the qualities of entities and on processes and meanings that are not experimentally examined or measured [if measured at all] in terms of quantity, amount, intensity, or frequency. Qualitative researchers stress the socially constructed nature of reality, the intimate relationship between the researcher and what is studied, and the situational constraints Human Development Functioning Prepared by: Ms. Mary Claudine N. Pineda, RPm that shape inquiry. Such researchers emphasize the value-laden nature of inquiry. They seek answers to questions that stress how social experience is created and given meaning. Basic Research Designs 1) Case Study – in-depth study of a single individual. 2) Ethnographic Study – in-depth study of a culture or subculture. 3) Correlational study – attempt to find positive or negative relationships between variables. 4) Experiment – A controlled procedure in which an experimenter controls the independent variable to determine its effect on the dependent variable; may be conducted in the laboratory or field. Important Terms Random assignment – assignment of participants to groups in such a way that each person has an equal chance of being placed in any group. Independent variable – in an experiment, the condition over which the experimenter has direct control. Dependent variable – in an experiment, the condition that may or may not change as a result of changes in the independent variable. Experimental group – in an experiment, the group receiving the treatment under study. Control group - in an experiment, a group of people similar to those in the experimental group, who do not receive the treatment under study. Placebo – an inert substance that has no known effects. Developmental Research Designs Cross-sectional Approach. The study of developmental differences was carried out by examining age differences among different people at different age levels at one point in time. Longitudinal Approaches. The study of developmental differences is carried out by collecting data on the same person or persons over a period of time. Sequential. Data are collected on successive cross-sectional or longitudinal samples. Ethics of Research BENEFICENCE – obligation to maximize potential benefits to participants and to minimize potential harm. RESPECT – respect for participants‟ autonomy and protection of those unable to exercise their own judgment. JUSTICE – inclusion of diverse groups together with sensitivity to any special impact the research may have on them.