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.
Adolescence is a transitional stage of physical and psychological development that generally occurs during the period from puberty to adulthood. Adolescence is usually associated with the teenage years, but its physical, psychological or cultural expressions may begin earlier or end later. Puberty typically begins during preadolescence, particularly in females. Physical growth and cognitive development can extend past the teens. Age provides only a rough marker of adolescence, and scholars have not agreed upon a precise definition. Some definitions start as early as 10 and end as late as 30. The World Health Organization definition officially designates an adolescent as someone between the ages of 10 and 19.
In sociology, a peer group is both a social group and a primary group of people who have similar interests (homophily), age, background, or social status. The members of this group are likely to influence the person's beliefs and behaviour.
Irreligion is the absence or rejection of religious beliefs or practices. It encompasses a wide range of viewpoints drawn from various philosophical and intellectual perspectives, including atheism, agnosticism, skepticism, rationalism, and secularism. These perspectives can vary, with individuals who identify as irreligious holding a diverse array of specific beliefs about religion or its role in their lives.
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.
The Oxford English Dictionary defines religiosity as: "Religiousness; religious feeling or belief. [...] Affected or excessive religiousness". Different scholars have seen this concept as broadly about religious orientations and degrees of involvement or commitment. Religiosity is measured at the levels of individuals or groups but scholars differ as to what behaviors would constitute religiosity. Sociologists of religion have observed that an individual's experience, beliefs, sense of belonging, and general behavior often are not congruent with their religious behavior, since there is much diversity in how one can be religious or not. Problems arise in measuring religiosity. For instance, measures of variables such as church attendance produce different results when different methods are used, such as traditional surveys as opposed to time-use surveys.
Religion in the United States is widespread and diverse, with the country being far more religious than other wealthy Western nations. An overwhelming majority of Americans believe in a higher power, engage in spiritual practices, and consider themselves religious or spiritual. Christianity is the most widely professed religion, with the majority of Americans being Evangelicals, Mainline Protestants, or Catholics.
Piaget's theory of cognitive development, or his genetic epistemology, is a comprehensive theory about the nature and development of human intelligence. It was originated by the Swiss developmental psychologist Jean Piaget (1896–1980). The theory deals with the nature of knowledge itself and how humans gradually come to acquire, construct, and use it. Piaget's theory is mainly known as a developmental stage theory.
Egocentrism is the inability to differentiate between self and other. More specifically, it is the inability to accurately assume or understand any perspective other than one's own. Egocentrism is found across the life span: in infancy, early childhood, adolescence, and adulthood. Although egocentric behaviors are less prominent in adulthood, the existence of some forms of egocentrism in adulthood indicates that overcoming egocentrism may be a lifelong development that never achieves completion. Adults appear to be less egocentric than children because they are faster to correct from an initially egocentric perspective than children, not because they are less likely to initially adopt an egocentric perspective.
Accurate demographics of atheism are difficult to obtain since conceptions of atheism vary considerably across different cultures and languages, ranging from an active concept to being unimportant or not developed. Also in some countries and regions atheism carries a strong stigma, making it harder to count atheists in these countries. In global studies, the number of people without a religion is usually higher than the number of people without a belief in a deity and the number of people who agree with statements on lacking a belief in a deity is usually higher than the number of people who self-identify as "atheists".
Emerging adulthood, early adulthood, or post-adolescence refers to a phase of the life span between late adolescence and early adulthood, as initially proposed by Jeffrey Arnett in a 2000 article from the American Psychologist. It primarily describes people living in developed countries, but it is also experienced by young adults in wealthy urban families in the Global South. The term describes young adults who do not have children, do not live in their own homes, and/or do not have sufficient income to become fully independent. Arnett suggests emerging adulthood is the distinct period between 20 and 29 years of age where young adults become more independent and explore various life possibilities.
According to Alberts, Elkind, and Ginsberg the personal fable "is the corollary to the imaginary audience. Thinking of themselves as the center of attention, the adolescent comes to believe that it is because they are special and unique.” It is found during the formal operational stage in Piagetian theory, along with the imaginary audience. Feelings of invulnerability are also common. The term "personal fable" was first coined by the psychologist David Elkind in his 1967 work Egocentrism in Adolescence.
In the United States, between 6% and 15% of citizens demonstrated nonreligious attitudes and naturalistic worldviews, namely atheists or agnostics. The number of self-identified atheists and agnostics was around 4% each, while many persons formally affiliated with a religion are likewise non-believing.
Psychology encompasses a vast domain, and includes many different approaches to the study of mental processes and behavior. Below are the major areas of inquiry that taken together constitute psychology. A comprehensive list of the sub-fields and areas within psychology can be found at the list of psychology topics and list of psychology disciplines.
In psychology, maturity can be operationally defined as the level of psychological functioning one can attain, after which the level of psychological functioning no longer increases much with age. However, beyond this, integration is also an aspect of maturation, such as the integration of personality, where the behavioral patterns, motives and other traits of a person are gradually brought together, to work together effectively with little to no conflict between them, as an organized whole, e.g., bringing a person's various motives together into a purpose in life. Case in point: adult development and maturity theories include the purpose in life concept, in which maturity emphasizes a clear comprehension of life's purpose, directedness, and intentionality, which contributes to the feeling that life is meaningful.
Church attendance is a central religious practice for many Christians; some Christian denominations, such as the Catholic Church require church attendance on the Lord's Day (Sunday); the Westminster Confession of Faith is held by the Reformed Churches and teaches first-day Sabbatarianism, thus proclaiming the duty of public worship in keeping with the Ten Commandments. Similarly, The General Rules of the Methodist Church also requires "attending upon all the ordinances of God" including "the public worship of God". The Lutheran Christian theologian Balthasar Münter stated that church attendance is the "foundation for the Christian life" as "the Christian Bible and the sacraments provide the framework for the faith"; he also states that it is important for believers because it aids in the prevention of backsliding, as well as offers "the company of other believers". Until 1791, the Kingdom of Great Britain required attendance at church services of the Church of England at least twice a year.
Moral development focuses on the emergence, change, and understanding of morality from infancy through adulthood. The theory states that morality develops across a lifespan in a variety of ways and is influenced by an individual's experiences and behavior when faced with moral issues through different periods of physical and cognitive development. Morality concerns an individual's reforming sense of what is right and wrong; it is for this reason that young children have different moral judgment and character than that of a grown adult. Morality in itself is often a synonym for "rightness" or "goodness." It also refers to a specific code of conduct that is derived from one's culture, religion, or personal philosophy that guides one's actions, behaviors, and thoughts.
Religious identity is a specific type of identity formation. Particularly, it is the sense of group membership to a religion and the importance of this group membership as it pertains to one's self-concept. Religious identity is not necessarily the same as religiousness or religiosity. Although these three terms share a commonality, religiousness and religiosity refer to both the value of religious group membership as well as participation in religious events. Religious identity, on the other hand, refers specifically to religious group membership regardless of religious activity or participation.
Spirituality affects both mental and physical health outcomes in the general United States population across different ethnic groups. Because of the nuanced definitions of spirituality and religiosity, the literature on spirituality is not consistent in definitions or measures resulting in a lack of coherence. However, taken as a whole, research tends to show that the effect of spirituality is positive, associated with better health outcomes. For those who engage in spirituality, it may serve as a buffer from negative life events, often moderating the relationship between negative life experiences and levels of anxiety or depression. The exception is when negative spiritual coping is practiced. This type of coping has negative health implications.
