Developmental psychology is the scientific study of how and why humans grow, change, and adapt across the course of their lives. Originally concerned with infants and children, the field has expanded to include adolescence, adult development, aging, and the entire lifespan. Developmental psychologists aim to explain how thinking, feeling, and behaviors change throughout life. This field examines change across three major dimensions, which are physical development, cognitive development, and social emotional development. Within these three dimensions are a broad range of topics including motor skills, executive functions, moral understanding, language acquisition, social change, personality, emotional development, self-concept, and identity formation.
Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spoken language, and in adults it can create difficulties with social interaction and at work. Hearing loss can be temporary or permanent. Hearing loss related to age usually affects both ears and is due to cochlear hair cell loss. In some people, particularly older people, hearing loss can result in loneliness.
Menopause, also known as the climacteric, is the time when menstrual periods permanently stop, marking the end of reproduction. It typically occurs between the ages of 45 and 55, although the exact timing can vary. Menopause is usually a natural change. It can occur earlier in those who smoke tobacco. Other causes include surgery that removes both ovaries or some types of chemotherapy. At the physiological level, menopause happens because of a decrease in the ovaries' production of the hormones estrogen and progesterone. While typically not needed, a diagnosis of menopause can be confirmed by measuring hormone levels in the blood or urine. Menopause is the opposite of menarche, the time when a girl's periods start.
Development of the human body is the process of growth to maturity. The process begins with fertilization, where an egg released from the ovary of a female is penetrated by a sperm cell from a male. The resulting zygote develops through mitosis and cell differentiation, and the resulting embryo then implants in the uterus, where the embryo continues development through a fetal stage until birth. Further growth and development continues after birth, and includes both physical and psychological development that is influenced by genetic, hormonal, environmental and other factors. This continues throughout life: through childhood and adolescence into adulthood.
An adult is a human or other animal that has reached full growth. The biological definition of the word means an animal reaching sexual maturity and thus capable of reproduction. In the human context, the term adult has meanings associated with social and legal concepts. In contrast to a non-adult or "minor", a legal adult is a person who has attained the age of majority and is therefore regarded as independent, self-sufficient, and responsible. They may also be regarded as a "major". The typical age of attaining legal adulthood is 18, although definition may vary by legal rights, country, and psychological development.
A toddler is a child approximately 1 to 3 years old, though definitions vary. The toddler years are a time of great cognitive, emotional and social development. The word is derived from "to toddle", which means to walk unsteadily, like a child of this age.
Young Adult The UN describes Young Adulthood as the period between the dependence of childhood and the independence of adulthood, being an indeterminate period generally from 20 to 59 followed by the Young Elderly stage from 60 to 75. Definitions and opinions on what qualifies as a young adult vary, with works such as Erik Erikson's stages of human development significantly influencing the definition of the term; generally, the term is often used to refer to adults in approximately the age range of 20s to 59 years, with some more inclusive definitions extending the definition into the early to last 50s.
A midlife crisis is a transition of identity and self-confidence that can occur in middle-aged individuals, typically 45 to 64 years old. The phenomenon is described as a psychological crisis brought about by events that highlight a person's growing age, inevitable mortality, and possible lack of accomplishments in life. This may produce feelings of intense depression, remorse, and high levels of anxiety; or the desire to achieve youthfulness, make drastic changes to their current lifestyle, or change past decisions and events. Studies on midlife crises show that they are less common than popularly believed, according to Vaillant (2012): in his 75-year longitudinal study on adult development, he found midlife crises were rare experiences for people involved in the study. The term was coined by Elliott Jaques in 1965.
The anal stage is the second stage in Sigmund Freud's theory of psychosexual development, taking place approximately between the ages of 18 months and three years. In this stage, the anal erogenous zone becomes the primary focus of the child's libidinal energy. The main social context for the experience is the process of toilet training, where anal pleasure becomes associated with the control of bowel movements.
Presbycusis, or age-related hearing loss, is the cumulative effect of aging on hearing. It is a progressive and irreversible bilateral symmetrical age-related sensorineural hearing loss resulting from degeneration of the cochlea or associated structures of the inner ear or auditory nerves. The hearing loss is most marked at higher frequencies. Hearing loss that accumulates with age but is caused by factors other than normal aging is not presbycusis, although differentiating the individual effects of distinct causes of hearing loss can be difficult.
Late-onset hypogonadism (LOH) or testosterone deficiency syndrome (TDS) is a condition in older men characterized by measurably low testosterone levels and clinical symptoms mostly of a sexual nature, including decreased desire for mating, fewer spontaneous erections, and erectile dysfunction. It is the result of a gradual drop in testosterone; a steady decline in testosterone levels of about 1% per year can happen and is well documented in both men and women.
In developmental psychology and developmental biology, a critical period is a maturational stage in the lifespan of an organism during which the nervous system is especially sensitive to certain environmental stimuli. If, for some reason, the organism does not receive the appropriate stimulus during this "critical period" to learn a given skill or trait, it may be difficult, ultimately less successful, or even impossible, to develop certain associated functions later in life. Functions that are indispensable to an organism's survival, such as vision, are particularly likely to develop during critical periods. "Critical period" also relates to the ability to acquire one's first language. Researchers found that people who passed the "critical period" would not acquire their first language fluently.
Neuroplasticity, also known as neural plasticity or brain plasticity, is the ability of neural networks in the brain to change through growth and reorganization. It is when the brain is rewired to function in some way that differs from how it previously functioned. These changes range from individual neuron pathways making new connections, to systematic adjustments like cortical remapping or neural oscillation. Other forms of neuroplasticity include homologous area adaptation, cross modal reassignment, map expansion, and compensatory masquerade. Examples of neuroplasticity include circuit and network changes that result from learning a new ability, information acquisition, environmental influences, pregnancy, caloric intake, practice/training, and psychological stress.
In psychology and psychotherapy, existential crises are inner conflicts characterized by the impression that life lacks meaning or by confusion about one's personal identity. Existential crises are accompanied by anxiety and stress, often to such a degree that they disturb one's normal functioning in everyday life and lead to depression. This negative attitude towards life and meaning reflects various positions characteristic of the philosophical movement known as existentialism. Synonyms and closely related terms include existential dread, existential vacuum, existential neurosis, and alienation. The various aspects associated with existential crises are sometimes divided into emotional, cognitive, and behavioral components. Emotional components refer to the feelings they provoke, such as emotional pain, despair, helplessness, guilt, anxiety, or loneliness. Cognitive components encompass the problem of meaninglessness, the loss of personal values or spiritual faith, and reflections about one's own mortality. Outwardly, existential crises often express themselves in addictions, anti-social and compulsive behavior.
Spermarche, also known as semenarche, is the time at which a male experiences his first ejaculation. It is considered to be the counterpart of menarche in girls. Depending on upbringing, cultural differences, and prior sexual knowledge, males may have different reactions to spermarche, ranging from fear to excitement. Spermarche is one of the first events in the life of a male leading to sexual maturity. It occurs at the time when the secondary sex characteristics are just beginning to develop. Researchers have had difficulty determining the onset of spermarche because it is reliant on self-reporting. Other methods to determine it have included the examination of urine samples to determine the presence of spermatozoa. The presence of sperm in urine is referred to as spermaturia.
Adult development encompasses the changes that occur in biological and psychological domains of human life from the end of adolescence until the end of one's life. Changes occur at the cellular level and are partially explained by biological theories of adult development and aging. Biological changes influence psychological and interpersonal/social developmental changes, which are often described by stage theories of human development. Stage theories typically focus on "age-appropriate" developmental tasks to be achieved at each stage. Erik Erikson and Carl Jung proposed stage theories of human development that encompass the entire life span, and emphasized the potential for positive change very late in life.
Stage-crisis view is a theory of adult development that was established by Daniel Levinson. Although largely influenced by the work of Erik Erikson, Levinson sought to create a broader theory that would encompass all aspects of adult development as opposed to just the psychosocial. This theory is characterized by both definitive eras as well as transition phases, whose purpose is to facilitate a smooth transition out of one era and into the next. According to his theory, various developmental tasks must be mastered as one progresses through each era; pre-adulthood, early adulthood, middle adulthood, and late adulthood. Crises are also experienced throughout the lifecycle and occur when one become burdened by either internal or external factors, such as during the midlife crisis that occurs during the midlife transition from early adulthood to middle adulthood.
The neural encoding of sound is the representation of auditory sensation and perception in the nervous system. The complexities of contemporary neuroscience are continually redefined. Thus what is known of the auditory system has been continually changing. The encoding of sounds includes the transduction of sound waves into electrical impulses along auditory nerve fibers, and further processing in the brain.
Margie E. Lachman is an American psychologist. She is the Minnie and Harold Fierman Professor of Psychology at Brandeis University, director of the Lifespan Developmental Psychology Lab and the director of the Boston Roybal Center for Active Lifestyle Interventions. She was editor of the Journal of Gerontology: Psychological Sciences (2000-2003), and has edited two volumes on midlife development. She is a fellow of the American Psychological Association, Division 20 and the Gerontological Society of America. Lachman's research is in the area of lifespan development with a focus on midlife and later life. Her current work is aimed at identifying psychosocial and behavioral factors that can protect against, minimize, or compensate for declines in cognition and health. She is conducting studies to examine long-term predictors of psychological and physical health, laboratory-based experiments to identify psychological and physiological processes involved in aging-related changes, especially in memory, and intervention studies to enhance performance and promote adaptive functioning through active engagement and physical activity.
Sandra Gordon-Salant is an American audiologist. She is a professor at the University of Maryland, College Park, where she is also director of the doctoral program in clinical audiology. Gordon-Salant investigates the effects of aging and hearing loss on auditory processes, as well as signal enhancement devices for hearing-impaired listeners. She is the senior editor of the 2010 book, The Aging Auditory System. Gordon-Salant has served as editor of the Journal of Speech, Language, and Hearing Research.
