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.
Alfred Adler was an Austrian medical doctor, psychotherapist, and founder of the school of individual psychology. His emphasis on the importance of feelings of belonging, family constellation and birth order set him apart from Freud and others in their common circle. He proposed that contributing to others was how the individual feels a sense of worth and belonging in the family and society. His earlier work focused on inferiority, coining the term inferiority complex, an isolating element which he argued plays a key role in personality development. Alfred Adler considered a human being as an individual whole, and therefore he called his school of psychology "Individual Psychology".
A sibling is a relative that shares at least one parent with the subject. A male sibling is a brother and a female sibling is a sister. A person with no siblings is an only child.
Imaginary friends are a psychological and a social phenomenon where a friendship or other interpersonal relationship takes place in the imagination rather than physical reality.
Birth order refers to the order a child is born in their family; first-born and second-born are examples. Birth order is often believed to have a profound and lasting effect on psychological development. This assertion has been repeatedly challenged. Recent research has consistently found that earlier born children score slightly higher on average on measures of intelligence, but has found zero, or almost zero, robust effect of birth order on personality. Nevertheless, the notion that birth-order significantly influences personality continues to have a strong presence in pop psychology and popular culture.
In psychology, inferiority complex is a consistent feeling of inadequacy, often resulting in the belief that one is in some way deficient, or inferior, to others.
A spoiled child or spoiled brat is a derogatory term aimed at children who exhibit behavioral problems from being overindulged by their parents or other caregivers. Children and teens who are perceived as spoiled may be described as "overindulged", "grandiose", "narcissistic" or "egocentric-regressed". When the child has a neurological condition such as autism, ADHD or intellectual disability, observers may see them as "spoiled”. There is no specific scientific definition of what "spoiled" means, and professionals are often unwilling to use the label because it is considered vague and derogatory. Being spoiled is not recognized as a mental disorder in any of the medical manuals, such as the ICD-10 or the DSM-IV, or its successor, the DSM-5.
An only child is a person with no siblings, by birth or adoption.
Self-disclosure is a process of communication by which one person reveals information about themselves to another. The information can be descriptive or evaluative, and can include thoughts, feelings, aspirations, goals, failures, successes, fears, and dreams, as well as one's likes, dislikes, and favorites.
Sibling rivalry is a type of competition or animosity among siblings, whether blood-related or not.
Individual psychology is a psychological method or science founded by the Viennese psychiatrist Alfred Adler. The English edition of Adler's work on the subject (1925) is a collection of papers and lectures given mainly between 1912 and 1914. The papers cover the whole range of human psychology in a single survey, and were intended to mirror the indivisible unity of the personality.
Environment and intelligence research investigates the impact of environment on intelligence. This is one of the most important factors in understanding human group differences in IQ test scores and other measures of cognitive ability. It is estimated that genes contribute about 20–40% of the variance in intelligence in childhood and about 80% in adulthood. Thus the environment and its interaction with genes account for a high proportion of the variation in intelligence seen in groups of young children, and for a small proportion of the variation observed in groups of mature adults. Historically, there has been great interest in the field of intelligence research to determine environmental influences on the development of cognitive functioning, in particular, fluid intelligence, as defined by its stabilization at 16 years of age. Despite the fact that intelligence stabilizes in early adulthood it is thought that genetic factors come to play more of a role in our intelligence during middle and old age and that the importance of the environment dissipates.
The relationship between fertility and intelligence has been investigated in many demographic studies. There is evidence that, on a population level, measures of intelligence such as educational attainment and literacy are negatively correlated with fertility rate in some contexts. However, genetic studies have shown no evidence for dysgenic effects in human populations. Theories about dysgenic and eugenic effects in human populations have historically been associated with scientific racism.
Alcoholism in family systems refers to the conditions in families that enable alcoholism and the effects of alcoholic behavior by one or more family members on the rest of the family. Mental health professionals are increasingly considering alcoholism and addiction as diseases that flourish in and are enabled by family systems.
Sibling deidentification is a cognitive identity-formation process that increases the extent to which one sibling in a sibling dyad defines his or her identity in terms of difference from other sibling. Although extremely common, not all siblings deidentify. Deidentification, as a process of difference, is in direct competition with processes that cause similarity in siblings, such as modeling and a shared environment. In most sibling relationships, all of these effects will exert influence on identity formation, some causing identification and some causing deidentification.
Siblings play a unique role in one another's lives that simulates the companionship of parents as well as the influence and assistance of friends. Because siblings often grow up in the same household, they have a large amount of exposure to one another, like other members of the immediate family. However, though a sibling relationship can have both hierarchical and reciprocal elements, this relationship tends to be more egalitarian and symmetrical than with family members of other generations. Furthermore, sibling relationships often reflect the overall condition of cohesiveness within a family.
Peer victimization is the experience among children of being a target of the aggressive behavior of other children, who are not siblings and not necessarily age-mates.
The Birth Order Book: Why You Are the Way You Are is a 1982 non-fiction book by Christian psychologist Kevin Leman on birth order and its potential influence on personality and development. An updated and revised version of the book was published in 1998 through Baker Publishing Group. Leman first learned about birth order while a student at the University of Arizona. Several notable psychologists including the founder of birth order theory Alfred Adler, and Jules Angst have disputed the effects of birth order on personality and other outcomes.
The Practice and Theory of Individual Psychology is a work on psychology by Alfred Adler, first published in 1924. In his work, Adler develops his personality theory, suggesting that the situation into which a person is born, such as family size, sex of siblings, and birth order, plays an important part in personality development. Adler is among the many therapists who have noted the significance and impact of the relationship between attitudes towards oneself and others, and highlighting the relationship between regard for self and love of another. Adler claimed that the tendency to disparage others arises out of feelings of inferiority. Adler also describes the self as part of a reflection of the thoughts of others, seeing self-esteem as determined, in part, by feelings toward significant others. According to Adler, people are inherently motivated to engage in social activities, relate to other people, and acquire a style of life that is fundamentally social in nature.
A firstborn is the first child born to in the birth order of a couple through childbirth. Historically, the role of the firstborn child has been socially significant, particularly for a firstborn son in patriarchal societies. In law, many systems have incorporated the concept of primogeniture, wherein the firstborn child inherits their parent's property. The firstborn in Judaism, the bechor, is also accorded a special position.
