Editing Developmental psychology (section)

==Theories==
===Psychosexual development===
{{Main|Psychosexual development}}
[[Sigmund Freud]] developed a theory that suggested that humans behave as they do because they are constantly seeking pleasure. This process of seeking pleasure changes through stages because people evolve. Each period of seeking pleasure that a person experiences is represented by a stage of psychosexual development. These stages symbolize the process of arriving to become a maturing adult.<ref>{{cite book |last1=Lantz |first1=Sarah E. |last2=Ray |first2=Sagarika |title=StatPearls |date=2025 |publisher=StatPearls Publishing |chapter-url=http://www.ncbi.nlm.nih.gov/books/NBK557526/ |chapter=Freud's Developmental Theory |pmid=32491458 }}</ref>

The first is the ''oral stage'', which begins at birth and ends around a year and a half of age. During the oral stage, the child finds pleasure in behaviors like sucking or other behaviors with the mouth. The second is the ''anal stage'', from about a year or a year and a half to three years of age. During the anal stage, the child defecates from the anus and is often fascinated with its defecation. This period of development often occurs during the time when the child is being toilet trained. The child becomes interested with feces and urine. Children begin to see themselves as independent from their parents. They begin to desire assertiveness and autonomy.

The third is the ''[[phallic stage]]'', which occurs from three to five years of age (most of a person's personality forms by this age). During the phallic stage, the child becomes aware of its sexual organs. Pleasure comes from finding acceptance and love from the opposite sex. The fourth is the ''latency stage'', which occurs from age five until puberty. During the latency stage, the child's sexual interests are repressed.

Stage five is the ''[[genital stage]]'', which takes place from puberty until adulthood. During the genital stage, puberty begins to occur.<ref>{{cite web| vauthors = McLeod S |title=Psychosexual Stages|url=http://www.simplypsychology.org/psychosexual.html|url-status=dead|archive-url=https://web.archive.org/web/20141219093455/http://www.simplypsychology.org/psychosexual.html|archive-date=2014-12-19|access-date=2014-11-10|website=SimplyPsychology}}</ref> Children have now matured, and begin to think about other people instead of just themselves. Pleasure comes from feelings of affection from other people.

Freud believed there is tension between the conscious and unconscious because the conscious tries to hold back what the unconscious tries to express. To explain this, he developed three personality structures: id, ego, and superego. The id, the most primitive of the three, functions according to the pleasure principle: seek pleasure and avoid pain.<ref name="Theories2">{{cite book|title=Theories of personality: understanding persons| vauthors = Cloninger SC |date=29 June 2012|publisher=Pearson Education|isbn=978-0-205-25624-2|edition=6th|location=Boston|pages=19–101}}</ref> The superego plays the critical and moralizing role, while the ego is the organized, realistic part that mediates between the desires of the id and the superego.<ref name="Snowden2">{{cite book|title=Teach Yourself Freud| vauthors = Snowden R |publisher=[[McGraw-Hill]]|year=2006|isbn=978-0-07-147274-6|pages=105–107}}</ref>

===Theories of cognitive development===
{{Main|Piaget's theory of cognitive development}}
[[Jean Piaget]], a Swiss theorist, posited that children learn by actively constructing knowledge through their interactions with their physical and social environments.<ref name="WoodWoodBoyd2">{{Cite book|title=Mastering the world of psychology|publisher=Allyn & Bacon|year=2006|edition=2| vauthors = Wood SE, Wood CE, Boyd D }}{{pn|date=January 2025}}{{isbn missing}}</ref> He suggested that the adult's role in helping the child learn was to provide appropriate materials. In his interview techniques with children that formed an empirical basis for his theories, he used something similar to [[Socratic questioning]] to get children to reveal their thinking. He argued that a principal source of development was through the child's inevitable generation of contradictions through their interactions with their physical and social worlds. The child's resolution of these contradictions led to more integrated and advanced forms of interaction, a developmental process that he called, "equilibration."

Piaget argued that intellectual development takes place through a series of stages generated through the equilibration process. Each stage consists of steps the child must master before moving to the next step. He believed that these stages are not separate from one another, but rather that each stage builds on the previous one in a continuous learning process. He proposed four stages: ''sensorimotor'', ''pre-operational'', ''concrete operational'', and ''formal operational''. Though he did not believe these stages occurred at any given age, many studies have determined when these cognitive abilities should take place.<ref name="Edpsych24">{{cite book|title=Edpsych : modules| vauthors = Reese-Weber L, Bohlin CC, Durwin M |publisher=McGraw-Hill Humanities/Social Sciences/Languages|isbn=978-0-07-809786-7|edition=2nd|location=New York|pages=30–132|date=2011-12-06}}</ref>

===Stages of moral development===
{{Main|Lawrence Kohlberg's stages of moral development}}
Piaget claimed that logic and morality develop through constructive stages.<ref name="higheststage2">{{cite journal| vauthors = Kohlberg L |year=1973|title=The Claim to Moral Adequacy of a Highest Stage of Moral Judgment|journal=Journal of Philosophy|publisher=The Journal of Philosophy |volume=70|issue=18|pages=630–646|doi=10.2307/2025030|jstor=2025030}}</ref> Expanding on Piaget's work, [[Lawrence Kohlberg]] determined that the process of moral development was principally concerned with justice, and that it continued throughout the individual's lifetime.<ref name="dissertation2">{{cite thesis |id={{ProQuest|301935075}} | vauthors = Kohlberg L |year=1958 |title=The Development of Modes of Thinking and Choices in Years 10 to 16 |degree = Ph.D. | publisher = University of Chicago }}{{pn|date=January 2025}}</ref>

He suggested three levels of moral reasoning; pre-conventional moral reasoning, conventional moral reasoning, and post-conventional moral reasoning. The pre-conventional moral reasoning is typical of children and is characterized by reasoning that is based on rewards and punishments associated with different courses of action. Conventional moral reason occurs during late childhood and early adolescence and is characterized by reasoning based on rules and conventions of society. Lastly, post-conventional moral reasoning is a stage during which the individual sees society's rules and conventions as relative and subjective, rather than as authoritative.<ref name="Adolescence3">{{cite book|title=Adolescence| vauthors = Steinberg L |publisher=McGraw-Hill Higher Education|year=2008|isbn=978-0-07-340548-3|edition=8th|location=Boston|pages=60–365|author-link=Laurence Steinberg}}</ref>

Kohlberg used the Heinz Dilemma to apply to his stages of moral development. The Heinz Dilemma involves Heinz's wife dying from cancer and Heinz having the dilemma to save his wife by stealing a drug. Preconventional morality, conventional morality, and post-conventional morality applies to Heinz's situation.<ref>{{cite journal |url=http://www.simplypsychology.org/kohlberg.html |title=Kohlberg | journal=SimplyPsychology | vauthors = McLeod S |year=2013 }}</ref>

===Stages of psychosocial development===
{{Main|Erikson's stages of psychosocial development}}German-American psychologist [[Erik Erikson]] and his collaborator and wife, [[Joan Erikson]], posits eight stages of individual human development influenced by biological, psychological, and social factors throughout the lifespan.<ref name="Orenstein Erikson's Stages"/> At each stage the person must resolve a challenge, or an existential dilemma. Successful resolution of the dilemma results in the person ingraining a positive virtue, but failure to resolve the fundamental challenge of that stage reinforces negative perceptions of the person or the world around them and the person's personal development is unable to progress.<ref name="Orenstein Erikson's Stages"/>

The first stage, "Trust vs. Mistrust", takes place in infancy. The positive virtue for the first stage is hope, in the infant learning whom to trust and having hope for a supportive group of people to be there for him/her. The second stage is "Autonomy vs. Shame and Doubt" with the positive virtue being will. This takes place in early childhood when the child learns to become more independent by discovering what they are capable of whereas if the child is overly controlled, feelings of inadequacy are reinforced, which can lead to low self-esteem and doubt.

The third stage is "Initiative vs. Guilt". The virtue of being gained is a sense of purpose. This takes place primarily via play. This is the stage where the child will be curious and have many interactions with other kids. They will ask many questions as their curiosity grows. If too much guilt is present, the child may have a slower and harder time interacting with their world and other children in it.

The fourth stage is "Industry (competence) vs. Inferiority". The virtue for this stage is competency and is the result of the child's early experiences in school. This stage is when the child will try to win the approval of others and understand the value of their accomplishments.

The fifth stage is "Identity vs. Role Confusion". The virtue gained is fidelity and it takes place in adolescence. This is when the child ideally starts to identify their place in society, particularly in terms of their gender role.

The sixth stage is "Intimacy vs. Isolation", which happens in young adults and the virtue gained is love. This is when the person starts to share his/her life with someone else intimately and emotionally. Not doing so can reinforce feelings of isolation.

The seventh stage is "Generativity vs. Stagnation". This happens in adulthood and the virtue gained is care. A person becomes stable and starts to give back by raising a family and becoming involved in the community.

The eighth stage is "Ego Integrity vs. Despair". When one grows old, they look back on their life and contemplate their successes and failures. If they resolve this positively, the virtue of wisdom is gained. This is also the stage when one can gain a sense of closure and accept death without regret or fear.<ref>{{Cite web | vauthors = Mcleod S |date=2013 |title=[Erik Erikson's Stages of Psychosocial Development] |url=https://www.simplypsychology.org/Erik-Erikson.html |language=en}}</ref>

===Stages based on the model of hierarchical complexity===
{{Main|Model of hierarchical complexity}}
[[Michael Commons]] enhanced and simplified [[Bärbel Inhelder]] and Piaget's developmental theory and offers a standard method of examining the universal pattern of development. The Model of Hierarchical Complexity (MHC) is not based on the assessment of domain-specific information, It divides the Order of Hierarchical Complexity of tasks to be addressed from the Stage performance on those tasks. A stage is the order hierarchical complexity of the tasks the participant's successfully addresses. He expanded Piaget's original eight stage (counting the half stages) to seventeen stages. The stages are:

# [[Model of hierarchical complexity|Calculatory]]
# [[Model of hierarchical complexity|Automatic]]
# [[Model of hierarchical complexity|Sensory & Motor]]
# [[Model of hierarchical complexity|Circular sensory-motor]]
# [[Model of hierarchical complexity|Sensory-motor]]
# [[Model of hierarchical complexity|Nominal]]
# [[Model of hierarchical complexity|Sentential]]
# [[Model of hierarchical complexity|Preoperational]]
# [[Model of hierarchical complexity|Primary]]
# [[Model of hierarchical complexity|Concrete]]
# [[Model of hierarchical complexity|Abstract]]
# [[Model of hierarchical complexity|Formal]]
# [[Model of hierarchical complexity|Systematic]]
# [[Model of hierarchical complexity|Metasystematic]]
# [[Model of hierarchical complexity|Paradigmatic]]
# [[Model of hierarchical complexity|Cross-paradigmatic]]
# [[Model of hierarchical complexity|Meta-Cross-paradigmatic]]

The order of hierarchical complexity of tasks predicts how difficult the performance is with an R ranging from 0.9 to 0.98.

In the MHC, there are three main axioms for an order to meet in order for the higher order task to coordinate the next lower order task. Axioms are rules that are followed to determine how the MHC orders actions to form a hierarchy. These axioms are: a) defined in terms of tasks at the next lower order of hierarchical complexity task action; b) defined as the higher order task action that organizes two or more less complex actions; that is, the more complex action specifies the way in which the less complex actions combine; c) defined as the lower order task actions have to be carried out non-arbitrarily.{{fact|date=January 2025}}

===Ecological systems theory===
{{Main|Ecological systems theory}}
[[File:Bronfenbrenner's_Ecological_Theory_of_Development_(English).jpg|thumb|{{center|Bronfenbrenner's ecological systems theory}}]]
Ecological systems theory, originally formulated by [[Urie Bronfenbrenner]], specifies four types of nested environmental systems, with bi-directional influences within and between the systems. The four systems are microsystem, mesosystem, exosystem, and macrosystem. Each system contains roles, norms and rules that can powerfully shape development. The microsystem is the direct environment in our lives such as our home and school. Mesosystem is how relationships connect to the microsystem. Exosystem is a larger social system where the child plays no role. Macrosystem refers to the cultural values, customs and laws of society.<ref>{{cite web|url=https://explorable.com/ecological-systems-theory|title=Ecological Systems Theory|website=Explorable Psychology Experiments| vauthors = Sincero SM }}</ref>

The microsystem is the immediate environment surrounding and influencing the individual (example: school or the home setting). The mesosystem is the combination of two microsystems and how they influence each other (example: sibling relationships at home vs. peer relationships at school). The exosystem is the interaction among two or more settings that are indirectly linked (example: a father's job requiring more overtime ends up influencing his daughter's performance in school because he can no longer help with her homework). The macrosystem is broader taking into account social economic status, culture, beliefs, customs and morals (example: a child from a wealthier family sees a peer from a less wealthy family as inferior for that reason). Lastly, the chronosystem refers to the chronological nature of life events and how they interact and change the individual and their circumstances through transition (example: a mother losing her own mother to illness and no longer having that support in her life).<ref name="Edpsych24"/>

Since its publication in 1979, Bronfenbrenner's major statement of this theory, ''The Ecology of Human Development'',<ref>{{cite book | vauthors = Bronfenbrenner U | date = 1979 | title = The Ecology of Human Development: Experiments by Nature and Design | location = Cambridge, MA | publisher = Harvard University Press | isbn = 0-674-22457-4}}</ref> has had widespread influence on the way psychologists and others approach the study of human beings and their environments. As a result of this conceptualization of development, these environments—from the family to economic and political structures—have come to be viewed as part of the life course from childhood through to adulthood.<ref name="Smith et al.2">{{Cite book|title= Understanding Children's Development |url = https://archive.org/details/understandingchi00smit/mode/2up      |publisher=Blackwell|edition=4|series=Basic psychology|location=Oxford, England| year = 2003 |isbn = 9780631228233 | oclc = 963696734|vauthors = Smith PK, Cowie H, Blades M }}</ref>

===Zone of proximal development===
{{Main|Zone of proximal development}}
[[Lev Vygotsky]] was a Russian theorist from the Soviet era, who posited that children learn through hands-on experience and social interactions with members of their culture.<ref>{{cite book | vauthors = Schacter DL, Gilbert DR, Wegner DM | title = Psychology | volume = 2 | location = New York, NY | publisher = Worth Publishers | date = 2011 }}</ref> Vygotsky believed that a child's development should be examined during problem-solving activities.<ref name="Yamagata-Lynch">{{Cite book |last=Yamagata-Lynch |first=Lisa C. |url=https://books.google.com/books?id=4nAFT-zyrtEC |title=Activity Systems Analysis Methods: Understanding Complex Learning Environments |date=2010-07-15 |publisher=Springer Science & Business Media |isbn=978-1-4419-6321-5 |language=en}}</ref> Unlike Piaget, he claimed that timely and sensitive intervention by adults when a child is on the edge of learning a new task (called the "zone of proximal development") could help children learn new tasks. Zone of proximal development is a tool used to explain the learning of children and collaborating problem solving activities with an adult or peer.<ref name="Yamagata-Lynch"/> This adult role is often referred to as the skilled "master", whereas the child is considered the learning apprentice through an educational process often termed "[[cognitive apprenticeship]]" Martin Hill stated that "The world of reality does not apply to the mind of a child." This technique is called "scaffolding", because it builds upon knowledge children already have with new knowledge that adults can help the child learn.<ref name="vygotsky782">{{Cite book|title=Mind in society: the development of higher psychological processes |publisher=Harvard University Press|year=1978|location=Cambridge, MA | jstor = j.ctvjf9vz4 | oclc = 3517053 | isbn = 9780674576285       |vauthors = Vygotsky LS |doi=10.2307/j.ctvjf9vz4 | url = https://archive.org/details/mindinsocietydev0000vygo }}</ref> Vygotsky was strongly focused on the role of culture in determining the child's pattern of development, arguing that development moves from the social level to the individual level.<ref name="vygotsky782" /> In other words, Vygotsky claimed that psychology should focus on the progress of human consciousness through the relationship of an individual and their environment.<ref name="vygotsky20102">{{cite book | vauthors = Yamagata-Lynch LC |title=Activity Systems Analysis Methods: Understanding Complex Learning Environments |date=15 July 2010 |publisher=Springer Science & Business Media |isbn=978-1-4419-6321-5 |edition=illustrated |url=https://books.google.com/books?id=4nAFT-zyrtEC}}</ref> He felt that if scholars continued to disregard this connection, then this disregard would inhibit the full comprehension of the human consciousness.<ref name="vygotsky20102" />

===Constructivism===
{{Main|Constructivism (psychological school)}}
Constructivism is a paradigm in psychology that characterizes learning as a process of actively constructing knowledge. Individuals create meaning for themselves or make sense of new information by selecting, organizing, and integrating information with other knowledge, often in the context of social interactions. Constructivism can occur in two ways: individual and social. Individual constructivism is when a person constructs knowledge through cognitive processes of their own experiences rather than by memorizing facts provided by others. Social constructivism is when individuals construct knowledge through an interaction between the knowledge they bring to a situation and social or cultural exchanges within that content.<ref name="Edpsych24"/> A foundational concept of constructivism is that the purpose of cognition is to organize one's experiential world, instead of the ontological world around them.<ref>{{cite book |doi=10.1017/cbo9780511752865 |title=Constructivism and Education |date=1998 |isbn=978-0-521-62135-9 |editor-last1=Larochelle |editor-last2=Bednarz |editor-last3=Garrison |editor-first1=Marie |editor-first2=Nadine |editor-first3=Jim }}{{pn|date=January 2025}}</ref>

Jean Piaget, a Swiss developmental psychologist, proposed that learning is an active process because children learn through experience and make mistakes and solve problems. Piaget proposed that learning should be whole by helping students understand that meaning is constructed.<ref>{{cite web|url=http://viking.coe.uh.edu/~ichen/ebook/et-it/cognitiv.htm|title=Overview of Cognitive Constructivism|website=Cognitive Constructivist Theories|access-date=2014-11-13|archive-url=https://web.archive.org/web/20141215094725/http://viking.coe.uh.edu/~ichen/ebook/et-it/cognitiv.htm|archive-date=2014-12-15|url-status=dead}}</ref>

===Evolutionary developmental psychology===
{{Main|Evolutionary developmental psychology}}
Evolutionary developmental psychology is a research paradigm that applies the basic principles of Darwinian [[evolution]], particularly [[natural selection]], to understand the development of human behavior and cognition. It involves the study of both the [[Genetics|genetic]] and environmental mechanisms that underlie the development of social and [[cognitive]] competencies, as well as the [[epigenetic]] ([[gene-environment interaction]]s) processes that adapt these competencies to local conditions.<ref name="Bjorklund Blasi Evolutionary Developmental Psychology">{{cite book |doi=10.1002/9780470939376.ch29 |chapter=Evolutionary Developmental Psychology |title=The Handbook of Evolutionary Psychology |date=2015 |last1=Bjorklund |first1=David F. |last2=Blasi |first2=Carlos Hernández |pages=828–850 |isbn=978-0-471-26403-3 }}</ref>

EDP considers both the reliably developing, species-typical features of ontogeny (developmental adaptations), as well as [[Differential psychology|individual differences]] in behavior, from an evolutionary perspective. While evolutionary views tend to regard most individual differences as the result of either random genetic noise (evolutionary byproducts)<ref>{{cite journal |last1=Tooby |first1=John |last2=Cosmides |first2=Leda |title=On the Universality of Human Nature and the Uniqueness of the Individual: The Role of Genetics and Adaptation |journal=Journal of Personality |date=March 1990 |volume=58 |issue=1 |pages=17–67 |doi=10.1111/j.1467-6494.1990.tb00907.x |pmid=2198338 }}</ref> and/or idiosyncrasies (for example, peer groups, education, neighborhoods, and chance encounters)<ref>{{cite book |last1=Pinker |first1=Steven |title=The Blank Slate: The Modern Denial of Human Nature |title-link=The Blank Slate |date=2002 |publisher=Viking |isbn=978-0-670-03151-1 |chapter=Children }}</ref> rather than products of natural selection, EDP asserts that natural selection can favor the emergence of individual differences via "adaptive developmental plasticity".<ref name="Bjorklund Blasi Evolutionary Developmental Psychology"/><ref name=":1">{{cite book |doi=10.1093/oso/9780195122343.001.0001 |title=Developmental Plasticity and Evolution |date=2003 |last1=West-Eberhard |first1=Mary Jane |isbn=978-0-19-512234-3 }}{{pn|date=January 2025}}</ref> From this perspective, human development follows alternative life-history strategies in response to environmental variability, rather than following one species-typical pattern of development.<ref name="Bjorklund Blasi Evolutionary Developmental Psychology"/>

EDP is closely linked to the theoretical framework of [[evolutionary psychology]] (EP), but is also distinct from EP in several domains, including research emphasis (EDP focuses on adaptations of ontogeny, as opposed to adaptations of adulthood) and consideration of proximate ontogenetic and environmental factors (i.e., how development happens) in addition to more ultimate factors (i.e., why development happens), which are the focus of mainstream evolutionary psychology.<ref name=":32">{{cite journal |last1=Hernàndez Blasi |first1=Carlos |last2=Bjorklund |first2=David F. |title=Evolutionary Developmental Psychology: A New Tool for Better Understanding Human Ontogeny |journal=Human Development |date=2003 |volume=46 |issue=5 |pages=259–281 |doi=10.1159/000071935 }}</ref>

===Attachment theory===
{{Main|Attachment theory}}
Attachment theory, originally developed by [[John Bowlby]], focuses on the importance of open, intimate, emotionally meaningful relationships.<ref>{{Cite book|url=https://books.google.com/books?id=x-Oki9MxalQC&pg=PA45|title=Attachment Theory: Social, Developmental, and Clinical Perspectives| vauthors = Goldberg S, Muir R, Kerr J |date=2013-04-15|publisher=Routledge|isbn=9781135890520}}</ref> Attachment is described as a biological system or powerful survival impulse that evolved to ensure the survival of the infant. A threatened or stressed child will move toward caregivers who create a sense of physical, emotional, and psychological safety for the individual. Attachment feeds on body contact and familiarity. Later [[Mary Ainsworth]] developed the [[Mary Ainsworth#Strange Situation|Strange Situation]] protocol and the concept of the secure base. This tool has been found to help understand attachment, such as the Strange Situation Test and the Adult Attachment Interview. Both of which help determine factors to certain attachment styles. The Strange Situation Test helps find "disturbances in attachment" and whether certain attributes are found to contribute to a certain attachment issue.<ref name=":02">{{cite journal |last1=Kanieski |first1=Mary Ann |title=Securing attachment: The shifting medicalisation of attachment and attachment disorders |journal=Health, Risk & Society |date=August 2010 |volume=12 |issue=4 |pages=335–344 |doi=10.1080/13698571003789682 }}</ref> The Adult Attachment Interview is a tool that is similar to the Strange Situation Test but instead focuses attachment issues found in adults.<ref name=":02" /> Both tests have helped many researchers gain more information on the risks and how to identify them.<ref name=":02" />

Theorists have proposed four types of attachment styles:<ref name="Schacter4402">{{cite book|title=Psychology|url=https://archive.org/details/psychologysecond00dani|url-access=limited| vauthors = Schacter DL, Gilbert DT, Wegner DM |publisher=Worth|year=2011|pages=[https://archive.org/details/psychologysecond00dani/page/n471 440]|isbn=9781429237192}}</ref> secure, anxious-avoidant, anxious-resistant,<ref name="Adolescence3"/> and disorganized.<ref name="Schacter4402" /> Secure attachment is a healthy attachment between the infant and the caregiver. It is characterized by trust. Anxious-avoidant is an insecure attachment between an infant and a caregiver. This is characterized by the infant's indifference toward the caregiver. Anxious-resistant is an insecure attachment between the infant and the caregiver characterized by distress from the infant when separated and anger when reunited.<ref name="Adolescence3" /> Disorganized is an attachment style without a consistent pattern of responses upon return of the parent.<ref name="Schacter4402" />

It is possible to prevent a child's innate propensity to develop bonds. Some infants are kept in isolation or subjected to severe neglect or abuse, or they are raised without the stimulation and care of a regular caregiver. This deprivation may cause short-term consequences such as separation, rage, despair, and a brief lag in cerebral growth. Increased aggression, clinging behavior, alienation, psychosomatic illnesses, and an elevated risk of adult depression are among the long-term consequences.<ref>{{Cite book|title=Exploring Psychology| vauthors = Myers D |publisher=Worth Publishers|year=2008|isbn=978-1-57259-096-0}}</ref>{{page needed|date=August 2015}}<ref>{{Cite book|title=A Level Psychology Through Diagrams| vauthors = Hill G |publisher=Oxford University Press|year=2001|isbn=978-0-19-918094-3}}</ref>{{page needed|date=August 2015}}\

According to attachment theory, which is a psychological concept, people's capacity to develop healthy social and emotional ties later in life is greatly impacted by their early relationships with their primary caregivers, especially during infancy. This suggests that humans have an inbuilt need to develop strong bonds with caregivers in order to survive and be healthy. Childhood attachment styles can have an impact on how people behave in adult social situations, including romantic partnerships.<ref name=":13">{{Cite journal |vauthors=Simpson JA |year=1990 |title=Influence of attachment styles on romantic relationships |journal=Journal of Personality and Social Psychology |volume=59 |issue=5 |pages=971–980 |doi=10.1037/0022-3514.59.5.971 }}</ref>

===Nature vs nurture===
{{Expert needed|Psychology|talk=|reason=Nature-nurture relationship is neither a dichotomy nor a debate among developmental psychologists.|date=February 2025}}
{{Main|Nature versus nurture}}
A significant concern of developmental psychology is the relationship between innateness and environmental influences on development. This is often referred to as "[[nature and nurture]]" or [[psychological nativism|nativism]] versus [[empiricism]]. A nativist account of development would argue that the processes in question are innate, that is, they are specified by the organism's [[genes]].<ref>{{cite journal |last1=Khalidi |first1=Muhammad Ali |title=Nature and Nurture in Cognition |journal=The British Journal for the Philosophy of Science |date=June 2002 |volume=53 |issue=2 |pages=251–272 |doi=10.1093/bjps/53.2.251 |jstor=3541766 }}</ref> What makes a person who they are? Is it their environment or their genetics? This is the debate of nature vs nurture.<ref>{{cite journal | vauthors = Collins WA, Maccoby EE, Steinberg L, Hetherington EM, Bornstein MH | title = Contemporary research on parenting. The case for nature and nurture | journal = The American Psychologist | volume = 55 | issue = 2 | pages = 218–232 | date = February 2000 | pmid = 10717969 | doi = 10.1037/0003-066x.55.2.218 }}</ref>

According to an empiricist viewpoint, those processes are learned through interaction with the environment. Today developmental psychologists rarely take such polarized positions with regard to most aspects of development; rather they investigate, among many other things, the relationship between innate and environmental influences. One of the ways this relationship has been explored in recent years is through the emerging field of [[evolutionary developmental psychology]].

The dispute over innateness has been well represented in the field of [[language acquisition]] studies. A major question in this area is whether or not certain properties of human language are specified genetically or can be acquired through [[learning]]. The empiricist position on the issue of language acquisition suggests that the language input provides the necessary information required for learning the structure of language and that infants acquire language through a process of [[statistical learning in language acquisition|statistical learning]]. From this perspective, language can be acquired via general learning methods that also apply to other aspects of development, such as [[perceptual learning]].<ref>{{cite journal | vauthors = Sameroff A | title = A unified theory of development: a dialectic integration of nature and nurture | journal = Child Development | volume = 81 | issue = 1 | pages = 6–22 | date = January 2010 | pmid = 20331651 | doi = 10.1111/j.1467-8624.2009.01378.x }}</ref>

The nativist position argues that the input from language is too impoverished for infants and children to acquire the structure of language. Linguist [[Noam Chomsky]] asserts that, evidenced by the lack of sufficient information in the language input, there is a [[universal grammar]] that applies to all human languages and is pre-specified. This has led to the idea that there is a special cognitive [[modularity of mind|module]] suited for learning language, often called the [[language acquisition device]]. Chomsky's critique of the behaviorist model of language acquisition is regarded by many as a key turning point in the decline in the prominence of the theory of behaviorism generally.<ref name="Schlinger">{{cite journal |last1=Schlinger |first1=Henry D. |title=The Long Good-Bye: Why B. F. Skinner's Verbal Behavior is Alive and Well on the 50Th Anniversary of Its Publication |journal=The Psychological Record |date=July 2008 |volume=58 |issue=3 |pages=329–337 |doi=10.1007/BF03395622 }}</ref> But Skinner's conception of "Verbal Behavior" has not died, perhaps in part because it has generated successful practical applications.<ref name="Schlinger" />

Maybe there could be "strong interactions of both nature and nurture".<ref>{{cite journal | vauthors = McClearn GE | title = Nature and nurture: interaction and coaction | journal = American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics | volume = 124B | issue = 1 | pages = 124–130 | date = January 2004 | pmid = 14681926 | doi = 10.1002/ajmg.b.20044 }}</ref>

===Continuity vs discontinuity===
One of the major discussions in developmental psychology includes whether development is discontinuous or continuous.

Continuous development is quantifiable and quantitative, whereas discontinuous development is qualitative. Quantitative estimations of development can be measuring the stature of a child, and measuring their memory or consideration span. "Particularly dramatic examples of qualitative changes are metamorphoses, such as the emergence of a caterpillar into a butterfly."<ref name="Crain, William C., 1943">{{Cite book| vauthors = Crain WC |url=https://www.worldcat.org/oclc/918135643|title=Theories of development : concepts and applications|date=2 October 2015|isbn=978-1-317-34322-6|edition=Sixth|location=London|oclc=918135643 |publisher=Routledge, Taylor & Francis Group}}</ref>

Those psychologists who bolster the continuous view of improvement propose that improvement includes slow and progressing changes all through the life span, with behavior within the prior stages of advancement giving the premise of abilities and capacities required for the other stages. "To many, the concept of continuous, quantifiable measurement seems to be the essence of science".<ref name="Crain, William C., 1943"/>

However, not all psychologists concur that advancement could be a continuous process. A few see advancement as a discontinuous process. They accept advancement includes unmistakable and partitioned stages with diverse sorts of behavior happening in each organization. This proposes that the development of certain capacities in each arrange, such as particular feelings or ways of considering, has a definite beginning and ending point. Nevertheless, there is no exact moment when a capacity suddenly appears or disappears. Although some sorts of considering, feeling or carrying on could seem to seem abruptly, it is more than likely that this has been developing gradually for some time.<ref>{{Cite book| vauthors = Carter L, Grivas J |url= https://www.worldcat.org/oclc/224074696 |title=Psychology for South Australia. Stage 1 |date=2004 |publisher=Jacaranda |isbn=0-7314-0094-1|location=Milton, Qld.|oclc=224074696}}</ref>

Stage theories of development rest on the suspicion that development may be a discontinuous process including particular stages which are characterized by subjective contrasts in behavior. They moreover assume that the structure of the stages is not variable concurring to each person, in any case, the time of each arrangement may shift separately. Stage theories can be differentiated with ceaseless hypotheses, which set that development is an incremental process.<ref>{{Cite book| vauthors = White FA, Hayes BK, Livesey DJ |author-link=Fiona A. White |url=https://www.worldcat.org/oclc/904034548|title=Developmental psychology: from infancy to adulthood|date=18 September 2015|isbn=978-1-4860-1827-7|edition=4th|location=Melbourne, Vic.|oclc=904034548}}</ref>

===Stability vs change===
This issue involves the degree to which one becomes older renditions of their early experience or whether they develop into something different from who they were at an earlier point in development.<ref>{{cite book |doi=10.4324/9781315789255-4 |chapter=Aging, Personality, and Social Change: The Stability of Individual Differences over the Adult Life Span |title=Life-Span Development and Behavior |date=2019 |last1=Alwin |first1=Duane F. |pages=135–186 |isbn=978-1-315-78925-5 }}</ref> It considers the extent to which early experiences (especially infancy) or later experiences are the key determinants of a person's development. Stability is defined as the consistent ordering of individual differences with respect to some attribute.<ref>{{Cite journal |last=Emmerich|first=Walter|date=1966 |title=Stability and Change in Early Personality Development |journal=Young Children |volume=21 |issue=4 |pages=233–243 |jstor=42641912 }}</ref> Change is altering someone/something.

Most [[Development of the human body|'''''human development''''']] lifespan developmentalists recognize that extreme positions are unwise. Therefore, the key to a comprehensive understanding of development at any stage requires the interaction of different factors and not only one.<ref>{{cite journal |last1=Orben |first1=Amy |last2=Tomova |first2=Livia |last3=Blakemore |first3=Sarah-Jayne |title=The effects of social deprivation on adolescent development and mental health |journal=The Lancet Child & Adolescent Health |date=August 2020 |volume=4 |issue=8 |pages=634–640 |doi=10.1016/S2352-4642(20)30186-3 |pmid=32540024 |pmc=7292584 |doi-access=free }}</ref>

===Theory of mind===
Theory of mind is the ability to attribute mental states to ourselves and others.<ref>{{cite journal |last1=Byom |first1=Lindsey J. |last2=Mutlu |first2=Bilge |title=Theory of mind: mechanisms, methods, and new directions |journal=Frontiers in Human Neuroscience |date=2013 |volume=7 |page=413 |doi=10.3389/fnhum.2013.00413 |pmc=3737477 |pmid=23964218 |doi-access=free }}</ref> It is a complex but vital process in which children begin to understand the emotions, motives, and feelings of not only themselves but also others. Theory of mind allows individuals to understand that others have unique beliefs and desires different from their own. This ability enables successful social interactions by recognizing and interpreting the mental states of others. If a child does not fully develop theory of mind within this crucial 5-year period, they can suffer from communication barriers that follow them into adolescence and adulthood.<ref>{{Cite journal |last1=Nilsson |first1=Kristine Kahr |last2=de López |first2=Kristine Jensen |date=2016 |title=Theory of Mind in Children With Specific Language Impairment: A Systematic Review and Meta-Analysis |journal=Child Development |volume=87 |issue=1 |pages=143–153 |doi=10.1111/cdev.12462 |jstor=24698538 |pmid=26582261 }}</ref> Exposure to more people and the availability of stimuli that encourages social-cognitive growth is a factor that relies heavily on family.<ref>{{Cite web |title=Theory of Mind {{!}} Simply Psychology |url=https://www.simplypsychology.org/theory-of-mind.html |access-date=2022-07-29 |website=www.simplypsychology.org}}</ref>