Gender-role development is one of the most important areas of human development. In fact, the sex of a newborn sets the agenda for a whole array of developmental experiences that will influence the person throughout his or her life. The often controversial study of the development of gender is a topic that is inherently interesting to parents, students, researchers, and scholars for several reason…
The term "generation gap," which came into popular and scholarly use during the late 1960s and early 1970s, refers to differences in values of older and younger generations. Initially, it was thought that adolescents needed to express opinions and internalize value systems that were distinct from their parents' to individuate successfully and create separate identities. But pa…
Genetic counseling is the professional guidance and education of individuals, families, or potential parents in matters concerning diseases with a genetic component. The process involves a trained genetic counselor who reviews medical records, collects a family history of genetic disorders in relatives, and investigates the scientific literature for known genetic causes. The Human Genome Project h…
The term "genotype" refers to the specific genetic makeup of an individual and is often used with reference to allelic or mutant differences between individuals at one or more genes. The genotype of an individual is the genetic information within an individual's specific DNA sequence that sets the limits upon which nongenetic parameters like environment modulate normal and abn…
Prior to the early twentieth century, scientific observations of children were not common. Arnold Gesell was one of the first psychologists to systematically describe children's physical, social, and emotional achievements, particularly in the first five years of life. In fact, the developmental norms established by Ge-sell and his colleagues are still used by pediatricians and psychologist…
Little consensus exists among professionals as to what defines a gifted child. According to the results of the Intelligence Quotient (IQ) Test, a child can be gifted intellectually (where the most frequently used defining score is an IQ of 130) or academically (a ninety-fifth percentile ranking). But a gifted child may also show exceptional talent in creativity, the performing arts, or athletics. …
Haim Ginott was a clinical psychologist, child therapist, parent educator, and author whose work has had a substantial impact on the way adults relate to children. He began his career as an elementary school teacher in Israel in 1947 before immigrating to the United States. There he attended Columbia University in New York City, earning a doctoral degree in clinical psychology in 1952. Ginott�…
A grandparent is the parent of a parent who traditionally has served as a comforting presence in a child's life. In contemporary society children's relationships with grandparents vary greatly depending on the stability of a child's nuclear family, physical distance, the frequency and type of contact, and the degree of emotional attachment. In some cases the ties are strictly …
Infancy is a time of rapid growth. Generally, children double their birth weight by five months of age, triple it by twelve months, and quadruple it by twenty-four months. During the toddler years growth stabilizes by around five years, and children grow in height faster than in weight. Steady growth continues from seven to ten years of age. Gains in the thickness of fat tissue are greater in girl…
Granville Stanley Hall, the first president of the American Psychological Association, was born in Ash-field, Massachusetts. Hall was enrolled in Williston Seminary, and then went to Williams College, where he graduated in 1867. Around 1870 Hall traveled to Germany, where he was influenced by Nature-philosophy, especially by its genetic (i.e., developmental) approach. After obtaining his doctorate…
The term "handedness" typically refers to a person's preference for the use of a particular hand in familiar, unimanual tasks such as handwriting and throwing a ball. Depending on the criteria used, 65 to 90 percent of adults are right-handed, about 4 percent are left-handed, and the rest are mixed-handed, preferring the right hand for some tasks and the left for others. The t…
Harry Harlow received his B.A. and Ph.D. in psychology from Stanford University and then joined the faculty at the University of Wisconsin, where he established the Psychology Primate Laboratory. When Harlow's lab joined the Wisconsin Regional Primate Laboratory in 1964, Harlow became the director of the merged research center. He is most famous for his scientific study of love. Starting in…
Head Start was launched in 1965 as part of the Lyndon Johnson administration's "war on poverty," with the goal of bridging the school-readiness gap that exists between disadvantaged and more privileged pre-school children. The program calls for extensive involvement of parents, and it attempts to provide the children with better preschool skills. Since its inception, Head Star…
The Healthy Start Initiative, a community-driven demonstration project begun in 1991, is the largest federal public health program dedicated to improving the health of mothers and infants in high-risk communities in the United States. Its original goal was to reduce infant mortality by 50 percent through community-driven strategies that provided direct, innovative prenatal services and health sys…
About 1 in 1,000 children demonstrates hearing loss to a level considered deaf or partially hearing and in need of special educational support. Severity of hearing loss may differ in one ear compared to the other and will vary greatly for different children. Reasons for language assessment vary and become particularly crucial if a child has reached school age and has difficulties with lessons. Tes…
Many aspects of human characteristics (such as height and eye color) are largely genetically determined. Psychology researchers, however, tend to be interested in dimensions that are relatively less determined by genetics—traits that subject more to environmental influences, such as how a person feels, acts, and thinks. Given that the degree of genetic determination appears to vary from one…
A developmental delay is diagnosed when a child does not reach a developmental milestone (for example, sitting, walking, or combining words) at the expected age, despite allowing for individual variation in the rate of development. Each year, many children are born at increased risk of a developmental disability or delay. Infant and preschooler development is a complex, dynamic process that begins…
The term "Hispanic" incorporates a diverse group of people comprised of individuals from a variety of countries and representing great diversity in socioeconomic status, age, history, and ethnicity. According to U.S. Bureau of the Census estimates for the year 2000, about 12 percent of the total population in the United States was Hispanic. While Hispanic people share a common langu…
Children who do not have a consistent, adequate nighttime residence are considered to be homeless. There are as many as 250,000 homeless children (birth to sixteen years of age) in the United States, including children who are living in shelters or "doubled up" with friends and relatives. Common causes of homelessness for families with children include poverty, lack of affordable hou…
Homework is a tool for reinforcing and expanding on concepts introduced in the classroom. It can help foster independence, self-discipline, and a love of learning in younger children and can improve an older child's performance on standardized tests. Critics of homework say that it overburdens children and can adversely affect a child's development by cutting in on leisure time and c…
The Human Genome Project began in earnest in 1990 as an international, publicly funded effort to determine the sequence of the three billion base pairs of human DNA. The major goals of the project are to identify and functionally characterize the estimated 30,000 to 40,000 genes in human genome and to address the ethical, legal, and social issues that will arise from the use of the project'…
A hypothesis may be thought of as a well-informed guess that is drawn from a theory or collection of ideas. It provides the basis from which a reasoned prediction about the relationship between two or more factors is made (e.g., early attachment and the child's later educational attainment). The prediction should define clearly the factors and the group of people within which the relationsh…
The process of developing an identity begins with the infant's discovery of self, continues throughout childhood, and becomes the focus of adolescence. Erik Erikson, a pioneer in the field of personality development, identified the goal of adolescence as achieving a coherent identity and avoiding identity confusion. Identity is multidimensional and may include physical and sexual identity, …
The term "imaginary audience" was introduced by David Elkind to refer to the tendency of adolescents to falsely assume that their appearance or behavior is the focus of other people's attention. Having an imaginary audience is believed to result in the self-consciousness that is characteristic of adolescence and is often linked conceptually with personal fable, which involves…
Imaginary playmates have fascinated psychologists, parents, and teachers for many years. Although psychologists have been writing about imaginary playmates since the late 1800s, only a handful of articles and book chapters exist on this topic, with only a few of those empirically based. Some experts think that children with imaginary playmates are likely to be between the ages of three and six, be…
Immunization is recognized as one of the greatest public health achievements of the twentieth century. The widespread use of immunization is responsible for dramatic reductions in, and in some cases the elimination of, specific infectious diseases. Selected immunizations are directed at high-risk populations. These populations include: (1) individuals with underlying immune system disorders, (2) i…
In vitro fertilization is the term for a process whereby a mature egg from the female and a sperm from the male are placed in culture media where fertilization can occur. For humans, the first clinically successful in vitro fertilization occurred in 1978. If accomplished, cell division results in six to eight cells in about forty-eight hours, or a blastocyst of 100 cells in about 120 hours. One or…
With bipartisan support, the 105th U.S. Congress and President Clinton signed into law on June 4, 1997, P.L. 105-76, the latest amendments to the IDEA. This reauthorized federal legislation is an education, early intervention, and civil rights law with the goal of ensuring an opportunity for all children and youth to learn and develop regardless of disability, from birth through age twenty-one. T…
Inductive reasoning is logical thinking that operates from specific cases to general principles. For example, a preschooler might conclude that dolphins are fish because they live in water and swim as fish do. As children develop more sophisticated thinking, they are able to employ deductive reasoning, in which they use general principles to form hypotheses. Adolescents, for example, might have he…
Infancy, the period between birth and eighteen to twenty-four months, has fascinated parents, philosophers, and developmental scientists perhaps more than any other period of the lifespan. The study of infants allows us to understand the origins of physical and psychological life. Furthermore, during no other period of life are physical and psychological changes more pervasive and rapid than in in…
Infant mortality is defined as the death of a live-born infant within the first year of life. As an indicator of a nation's health status, infant mortality can serve as a reflection of a society's available resources and technology (including social distribution, access, and use), the status of women in society, and the health care provided to the most vulnerable segments of the popu…
Accidents, according to dictionary definitions, are events that happen by chance and are not predictable and therefore are not preventable. In contrast, from a public health perspective, injuries were first clearly conceptualized by William Haddon (1964) as damage done to the body as a result of often predictable and therefore preventable energy exchange. This energy exchange may be kinetic, therm…
Intelligence is the ability to solve problems. It is also commonly referred to as practical sense or the ability to get along well in all sorts of situations. People cannot see, hear, touch, smell, or taste intelligence. On the other hand, the more they have, the better able they are to respond to things around them. Anyone interested in understanding intelligence will find many theories, definiti…
The Internet—also called the World Wide Web, or web—is a vast system of connections among individual computers and computer networks, allowing information and programmed activities to be easily shared by individuals around the world. According to the National Center for Education Statistics (NCES), over 90 percent of primary school students in the United States report using the Inter…
Juvenile delinquency refers to the violation of a criminal law by a juvenile. In most states a juvenile is anyone under age eighteen, but in some states a person is considered an adult at age sixteen or seventeen. If a juvenile has committed an act that would be a crime if committed by an adult, then the juvenile has committed juvenile delinquency. Moreover, juvenile delinquency includes acts that…