Which Research Designs are Used to Study Development?

Longitudinal Design: one group of people is followed and assessed at different times as the group ages.
Cross-Sectional Design: A study in which a representative cross section of the population is tested or surveyed at one specific time.
Cross-Sequential Design: A research method in which a cross-section of the population is chosen and then each cohort is followed for a short period of time. Much less susceptible to bias, therefore yields more accurate data than a cross sectional study.

How Do Psychologists Explain Development?
Developmental psychologists learn how and why the brain and body change throughout our life span through the study of developmental psychology. In order to help developmental psychologists understand the impact of environment and heredity (the nature-nurture issue), studies of identical twins have become common. Identical twins have the same genotype, and we have discovered that hereditary effects show up more strongly.These studies attempt to measure the specific impacts and interaction between "nature" and "nurture". Identical twins separated at birth and identical twins who were raised together can be compared to test this theory. Fraternal twins, however, only share about 50% of their genes and are usually used as a control group. The common question concerning people, including twins, is: At what point do children become adults? Many psychologists question if there is a pattern to the development stages we go through. Based on the continuity view, change is gradual and continuous. For example, children become more skillful in thinking, talking, or acting in much the same way that they become taller: through gradual developmental process. On the other hand, some see development as a sequence of changes that produce different behaviors in different age-specific life periods, such as infancy, childhood, and adolescence. This is known as the discontinuity view. People who accept the discontinuity view also approve of developmental stages. The developmental stages are periods of life initiated by distinct transitions in physical or psychological functioning. People tend to go through the same stages in the same order but maybe different rates.


Chromosomes, Genes, and DNA: Two factors make an individual unique: genetic makeup and experiences. The genetic makeup, inherited from the biological mother and father, is called the genotype. The genotypes create observable physical characteristics called phenotypes. The inherited traits are encoded in cells. In each cell of the human body there are 23 pairs of chromosomes. The number of chromosomes can help determine the species while the types of sex chromosomes determine the gender. Inside each chromosome there are genes. A gene is the part of a chromosome that contains the information that becomes our physical and non-physical traits. Inside each gene there is a sequence of DNA, which provides the chemical basis for the genetic code. All of this genetic information becomes physical traits by encoding proteins.


What Capabilities Does the Child Possess?

People used to believe that babies are born as "blank slates;" however, it is now suggested that babies are born with innate abilities, such as knowing what they like (regarding taste and smell) or scanning their surroundings (although their vision is poor at first). They also have a very strong sense of hearing and behavioral reflexes that promote survival such as sucking, cooing, crying, and grasping. Newborns have innate (inborn) abilities for finding nourishment, interacting with others, and avoiding harmful situations, while the developing abilities of infants and children rely more on learning. Learning is effective to promote survival. For example, nourishment by suckling, and get attention by cooing and crying. These innate abilities develop in three developmental periods, beginning with the prenatal period in the womb. The child becomes a zygote after an egg is fertilized. After ten days of conception, an embryo is formed by the division of cells. This determines how all the organs will later be found in the newborn infant when it begins to form. After approximately 8 weeks, the embryo has grown into a fetus, and spontaneous movements begin to happen, commanded by the somatic nervous system. By this time the fetus has grown about 7 inches long. The placenta separates the fetus' and mother's bloodstreams, but allows nutrients and waste products to be exchanged. It is no longer believed that the placenta can protect the fetus from all teratogens, and many mothers now make precautions by monitoring their diets and drug intake. The most common teratogens are alcohol, drugs, and other harmful substances the mother takes in during her pregnancy. The next developmental period is the neonatal period, which ranges from birth to one month of age. Newborn babies in the neonatal period have many innate abilities, like the grasp reflex and postural reflex. In Harlow's Monkey experiment, it was shown that baby monkeys seek contact comfort over food.

The next stage, infancy, usually ends around 18 months to two years of age. It is between the neonatal period and the establishment of language. During infancy, the newborn develops an emotional connection with the parent known as attachment. Another important part of infancy is the development of neural connections and the connecting of potential brain circuits. During infancy, babies are constantly using classical conditioning to learn about important sensory events. Another form of learning, which occurs during infancy, is the process of imprinting. Imprinting is the process in which some animals develop an attachment to the first moving object they see and hear. An example of imprinting are birds learning to follow an ultra-light aircraft instead of their mother. Imprinting is associated more with animals than humans. Contact comfort is stimulation derived from the physical touch of a caregiver. Contact comfort safeguards the infant's survival by giving the infant security, a feeling of protection, and the support it needs. The infant eventually goes through maturation, which is the process of a human going through pre-programmed events, such as puberty or even menopause.

What Are the Developmental Tasks of Infancy and Childhood?




The abilities to think, reason, and build relationships are important tasks that develop during infancy and childhood. According to Piaget's theory, cognitive development is the overall idea of a toddler's growing interest in its surroundings. The first idea Piaget approached were schemas, which are "mental structures" that guide a developing child's thoughts. For example, when you hear four-legged, friendly animal that barks you think of a dog. Assimilation and accommodation are two dynamic processes which Piaget believes contributes to all cognitive growth. Assimilation modifies new information to fit with existing schemas while accommodation restructures and modifies schemas to incorporate new information. An example of accommodation is a child's simplistic "bird" schema, which includes any flying object, undergoes accommodation when the child learns that a butterfly is not a bird. Piaget theorized that a child goes through stages in cognitive development. The sensorimotor stage (0-2 years), is the time of development where innate and reflexive behaviors are explored. A mental image of an object, or a mental representation, allows a child to form images of objects and apply them to rational thinking. After this is established, the child can apply object permanence to know that an object exists in the world even when it cannot be seen. The preoperational stage (2-7 years), marks the well-developed mental representations and language that have been gained. In this stage, the self-centered inability to accept that ideas exist outside one's own, egocentrism, is eliminated. Animistic thinking is a preoperational mode of thought in which inanimate objects have emotions and motives. A preoperational child is unable to take account for more than one aspect of an object at a time, also referred to as centration. In addition, they are unable to think through a series of events in reverse order, which is referred to as irreversibility. Once the child reaches 7-11 years of age, they enter the concrete operational stage. They understand conservation and are also able to start mental operations. The final stage is the formal operational stage, which occurs through adolescence and marks the appearance of abstract thought.

Emotional and social development continues. The child develops a theory of mind, which helps them understand that other people can think too. This helps the child to be more sociable and start making friends. For example, being given a present, or spoken to angrily. From the "nature" viewpoint, psychologists believe that temperament influences our responsiveness to others. For example, shy babies are more easily frightened and less socially responsive than bold babies. People are then less likely to interact and be playful with the shy baby. Although nature is not the only effect, a shy babies parents might encourage her to interact; That child might end up becoming outgoing which was unpredicted (nurture). From the "nurture" viewpoint, psychologists have found many environmental factors that influence socialization.

What Changes Mark the Transition of Adolescence?

Theorists originally assumed that most human development occurred before adolescence. However, modern researchers disagree. Adolescence is the period following the onset of puberty during which a young person develops from a child into an adult. In some cultures, adolescence is not acknowledged; they believe that their people go directly from childhood to adulthood, a conversion which is achieved through cultural procedures or rites of passage. In our culture, we believe that adolescents are confronted with four major developmental tasks including physical maturation, cognitive development, and social-emotional issues. Sexual feelings/impulses and the development of moral standards are also included with the four major developmental tasks.

The most obvious aspect of physical maturation is the pubescent growth spurt, experienced two to three years before puberty. In the United States, males begin puberty around the age of 14 while females begin puberty between the ages of 11 and 15. During these ages, primary sex characteristics change as well as secondary sex characteristics. When the primary and secondary sex characteristics begin to change, the teenagers begin to become more aware of their appearance, often judging themselves based on what others think of them. Cognitive growth, in concordance with the final Piaget stage, allows the adolescent to have abstract and complex thoughts. Cognitive development is a formal operational stage where the individual starts their abstract thinking, which allows them to approach problems with a broad sense of cause, effect, and outcomes. This contributes to the frequent risk-taking behaviors among adolescents and the obsession over body image, sex, and social-emotional issues.

According to Erik Erikson, the biggest problem during adolescence is discovering one's identity. Certain social and emotional issues have the power to influence one's self image, which he classified into eight psychosocial stages. Erikson stresses that a satisfactory image must be discovered in order to have an adequate self-concept. Influences such as peers, depression, and delinquency have the ability to alter one's image during adolescence. Along with physical maturity, a new awareness of sexual feelings and impulses come into play during adolescence. The development of a sexual identity is important to adolescence because it defines sexual orientation and guides sexual behavior. Lawrence Kohlberg's stages of moral reasoning change from concrete and self-centered reasons to more abstract ideas of right and wrong. He explained stages of moral development and the earlier stages were based on self-interest while the more advanced stages were based on universal principles of social good and formal operational stages. However, Carol Gilligan disagreed with Kohlberg's stages, saying they were too male-centered.

What Developmental Challenges Do Adults Face?

Freud thought that adult development was driven by love and work. Maslow theorized that the needs were love and belonging; when satisfied they allow the emergence of esteem and fulfillment. Other theorists say that the basic needs divide into affiliation and achievement or competence needs. Many of these ideas posed the same ideal of affiliative needs as a theme of adulthood. Throughout life, nature and nurture continue to produce changes. Erikson proposes his theory of intimacy vs. isolation: those who are intimate (sexually, emotionally, and morally), will be healthier overall and lead a better life than those who isolate themselves. Isolated individuals are more susceptible to mental disorders, such as anxiety or depression. "We are a social people," stated Erikson, who believed that we need positive human interaction in order to continue development. According to Erikson, you must know who and what you are before you can begin to love someone else and share your life with that person. However in changing times, young adults tend to live with each other before marriage. Further complicating matters, marriage sometimes occurs more than once in an individual's life, which is said to be caused by individuals not meeting their identity before seeking intimacy. Erikson said those who met the challenges of identity and intimacy will now move on to generativity vs. stagnation (during middle adulthood). Generativity, according to Erikson, is a way to feel fulfilled later in your life. People in this phase generally broaden their focus beyond themselves and reach out to the community. Research shows that adults expressing a strong sense of generativity report high life satisfaction. Those who reach this stage without first successfully making it through identity and intimacy will often have a midlife crisis. Those people who have a midlife crisis start to think about previous decisions. Most, however, don't experience such an event. The next of Erikson's stages is ego-integrity vs. despair. Ego-integrity is involved with the individual looking back on life without regret and enjoying a sense of wholeness. However, those with unfulfilled aspirations feel despair and self-depreciation. In this stage, adults start to worry about their health and old age. A common worry of older people is Alzheimer's disease, a degenerative disorder of the brain that produces both diminished thinking abilities and memory problems. It can lead to emotional trauma for both the affected individual and their families, and can ultimately cause death. Elisabeth Kubler-Ross explained that in later adulthood, individuals must go through five stages of death and dying: denial (lying to yourself), anger (do not want to accept), bargaining (praying to god they will do anything to get better), depression (sadness and being alone), and acceptance (enjoys time they have left). Not everyone develops in the same way or in the same time frame, much like normal development.

Parenting Styles

Adults who choose to be parents are also faced with developmental challenges in their parenting styles. There are three distinguished types of parenting styles including authoritative, authoritarian, and permissive (neglectful and indulgent).
  • Authoritative parents are likely to listen to a child's viewpoint, use non-physical punishment, and set clear limits. Children raised by parents who are primarily authoritative are usually competent, independent, happier, self-reliant, and more successful.
  • Authoritarian parents are harsher, more uncompromising, and hold punishment as a form of correction. This type of parenting style deals with the individual obeying their parents completely and being reprimanded if they don't. These parents frequently degrade their child and are cold and rejecting. As a result the children will often rebel against their parents in negative and self-destructive ways.
  • There are two types of permissive parenting. A permissive neglectful parent won't be involved with their child and will let the child do whatever they want until it interferes with what the parent wants. A permissive indulgent parents is too involved with their child and lets their child (who they believe to be perfect) to do whatever they want. Children of both permissive parents will become selfish, dependent, unpopular, and will not have good social skills.

Effects of Day Care

Over half the mothers in the U.S. with kids under the age of three are employed. Most children thrive in day care, but some poor-quality day cares force children to become aggressive, maladjusted, or depressed. Day care in itself is neither good nor bad. It is the quality of the care that matters.

School and Leisure Influences

Most children take up their free time by watching television, talking on the phone, or being on the internet. The majority of the nation's children, however, use their free time to hang out with friends. They also use it to participate in after school activities, like clubs and sports.

Quizlet (Redo and Practice Test)