Research figure: John Bowlby · Written by Artificial Sapiens
John Bowlby's Attachment and Loss, Volume I: Attachment (1969) is the foundational book in which Bowlby systematically explained the young child's bond with a familiar caregiver as an organized behavioral system shaped by evolutionary pressures, developed through experience, and regulated by conditions of safety and threat. The book's central argument is that seeking a protective person's proximity has its own biological and psychological function. Attachment does not have to be derived from feeding, dependency, or the satisfaction of other drives. By bringing ethology, control-systems reasoning, direct developmental observation, and psychoanalytic questions into one framework, the volume provided the theoretical architecture for a major research program in developmental psychology. The original 1969 bibliographic record, the 1982 revised edition, and Bretherton's historical reconstruction document the volume's scope and subsequent development.
What the First Volume Set Out to Explain
The question that organizes Attachment is deceptively ordinary: why does an infant become strongly attached to particular people, and what makes the child's searching, clinging, crying, greeting, following, and exploration intelligible as a coordinated system? Bowlby approached these activities as observable elements of an organized relationship. Their significance depends on the situation, the identity and availability of the attachment figure, the child's state, and the likely consequences of gaining or losing proximity. He asked how such behavior develops, what activates or terminates it, and what biological function its organization might serve. The 1969 publisher record identifies the child's tie to the mother, the nature of instinctive behavior, and the development and operation of attachment behavior as the book's central subjects (Bowlby, 1969).
This is a work of theory construction and disciplined synthesis rather than a single experiment establishing a decisive result. Bowlby combined observations of children separated from caregivers, published developmental studies, animal research, and models of behavioral control. The resulting explanations generate testable propositions, but their historical presence in the book should be distinguished from empirical validation obtained afterward. That distinction is central to reading a foundational scientific text responsibly.
Publication History: 1969 and the Revised 1982 Edition
The first edition appeared in 1969 as Volume I of Attachment and Loss, published in the United States by Basic Books and in Britain by the Hogarth Press and the Institute of Psycho-Analysis. It began the three-volume undertaking subsequently completed by Separation: Anxiety and Anger (1973) and Loss: Sadness and Depression (1980). The first volume establishes the positive organization and developmental basis of the attachment bond; the later volumes address threats to it, separation, anxiety, anger, bereavement, and loss. Accordingly, the argument of Volume I should be read on its own terms, without importing later volumes' specific accounts of mourning into its chapters (Bowlby, 1969; Bowlby, 1982).
The second edition of Attachment, issued in 1982, incorporated substantial revisions and two new chapters in light of changing theory and empirical work. The book's later printings often circulate under the short title Attachment, sometimes with additional editorial material. A claim that appears in a 1982 text therefore needs to be identified as part of the revised edition unless it can also be documented in 1969. Page numbers, chapter arrangements, prefaces, and pagination can vary across the original, the revision, and later reprints. The Basic Books edition record explicitly identifies the two new chapters and major revision; Bowlby's retrospective essay provides a contemporary statement of the intellectual development of the project.
The Problem of Explanation: From Psychoanalytic Drives to Attachment
Why feeding alone did not explain the bond
In influential psychoanalytic accounts of Bowlby's formative period, the child's relationship to the mother was frequently interpreted through the organization of drives, feeding, gratification, and internal fantasy. Bowlby regarded that explanatory vocabulary as insufficient for the observed selectivity, persistence, and distress of the infant's attachment to a particular individual. Children seek familiar caregivers when frightened even when they are not hungry; reunion and accessibility can regulate conduct independently of obtaining food. Bowlby's earlier 1958 paper, The Nature of the Child's Tie to His Mother, had developed the challenge that Volume I expanded into a broader system of behavioral explanation.
The conceptual change concerns what counts as the phenomenon requiring explanation. An infant's attachment is more than the aggregate of behaviors that happen to occur near an adult. Crying may be directed toward restoring contact, following may maintain access, and the organization of these acts changes as locomotion, discrimination, memory, and experience develop. Bowlby was attempting to explain the conditions under which different behaviors become coordinated around the same protective outcome. This is why the 1969 volume devotes considerable attention to instinctive behavior before treating attachment itself (Bowlby, 1969; Bretherton, 1992).
The relation to Freud and other analytic traditions
Bowlby remained engaged with psychoanalytic problems about early relationships, emotional development, anxiety, and later psychopathology. His proposed solution shifted the explanatory emphasis toward observable relationships and the prospective study of development. Instead of only reconstructing childhood from an adult symptom, researchers could examine caregiving conditions and infant behavior directly, follow developmental pathways, and compare hypotheses against observations. This shift explains why the book matters both to the history of psychoanalysis and to the rise of empirical developmental psychology. It also helps distinguish its argument from an attempt to discard the study of emotion or internal experience (Bretherton, 1992).
How the Book Is Organized
The initial problem and an alternative model of instinct
The opening portion lays out Bowlby's point of view and the observations that a satisfactory theory must explain. It then introduces a model of instinctive behavior informed by ethology, evolutionary reasoning, and feedback control. Rather than assuming that every characteristic act unfolds as a rigid chain, the account permits organized, flexible behavior to vary with both the organism's condition and the environment. This creates a vocabulary for asking how multiple component behaviors cooperate toward an outcome (Bowlby, 1969).
Behavioral systems, activation, and feeling
Subsequent chapters consider behavioral systems, circumstances that activate or terminate them, their coordination or competition, and the relation of evaluation, emotion, and behavior. The analytical importance of these chapters lies in the idea that apparently disparate acts can serve a functional organization. A child who looks back while exploring, moves toward a caregiver after an unfamiliar sound, and resumes play after receiving reassurance may be responding to changing conditions within a linked pattern of regulation. This is a conceptual reconstruction of behavior, not an assertion that every historical feedback metaphor has been verified as a literal neural circuit.
Attachment behavior and its development
The attachment-focused portion considers the child's tie, the possible evolutionary functions of staying near caregivers, evidence from other species, human observations, and attachment's changing expression as the child matures. The developmental emphasis is crucial. The neonatal repertoire, early social responsiveness, selective preference, directed proximity seeking, and increasingly sophisticated regulation are different stages of organization; they should not be compressed into the assumption that a newborn possesses a fully formed, adult-like relationship representation. The original volume investigates the transition from broadly social responses to discriminating bonds, within environmental and maturational constraints (Bowlby, 1969).
Ethology and Evolutionary Function
Bowlby's use of ethology redirected discussion of early relationships toward the functions behavior could have served during human evolutionary history. Ethologists such as Konrad Lorenz and Niko Tinbergen influenced the vocabulary of species-characteristic behavior and environmental releasing conditions; research on primates and other animals supplied comparative observations. Bowlby treated the child's tendency to approach and remain near a familiar protective person as a potentially adaptive solution to danger during immaturity. This is a functional, evolutionary proposal about why an organized system could exist, separate from the developmental question of how an individual child's bond emerges (Bretherton, 1992).
An evolutionary function does not specify one obligatory family arrangement, establish that all behaviors have the same origin, or prove that a particular caregiver is biologically irreplaceable. The explanatory target is the maintenance or restoration of protection in an environment where young children depend on adults. Ethological reasoning shaped the theory's hypotheses; the scope of their application to human caregiving must be assessed through human developmental evidence. Contemporary findings about attachment security to mothers and fathers are relevant to evaluating the historical mother-centered language of the book (Madigan et al., 2024).
Cybernetics, Feedback, and the Attachment Behavioral System
Goal-directed regulation of proximity
One of Volume I's most influential moves is to describe attachment through ideas derived from control-systems theory. A control system can be thought of as monitoring conditions, comparing them with a set goal, and adjusting behavior as circumstances change. Bowlby's attachment system does not require a child to repeat a fixed motor pattern. Crying, crawling, reaching, following, calling, or seeking contact may become relevant at different ages and in different environments because they can contribute to preserving an accessible protective relationship. Actual distance, visibility, perceived availability, and threat are among the changing circumstances around which such actions are organized (Bowlby, 1969).
The phrase goal-corrected captures the flexibility of this account. The same goal can be pursued through different behaviors; an effective action can change when the caregiver moves, a barrier intervenes, or the child learns that signaling from a distance is sufficient. Goal correction in this theoretical sense describes regulatory organization. It does not claim that very young children consciously calculate a control algorithm or possess explicit propositions about evolutionary survival.
Activation, termination, and competing activities
Attachment behavior becomes especially salient when a child is alarmed, tired, ill, uncertain, or separated. Its intensity and expression may recede when contact or reassurance is restored and the environment appears manageable. Play, exploration, social interaction, and attachment seeking can compete for behavioral priority. A familiar caregiver's accessibility makes it possible for the child's attention to shift back toward exploration. Bowlby's broader systems approach offered a way to connect these changing activities in a developmental account rather than treating them as unrelated reflexes.
Modern descriptions often distinguish a secure haven, sought during distress, and a secure base, from which exploration proceeds. Mary Ainsworth's fieldwork and later empirical program were especially important in articulating and operationalizing secure-base behavior. The distinction between Bowlby's general control-systems architecture and Ainsworth's evidence and observational methods protects their respective contributions from historical conflation (Bretherton, 1992; Ainsworth et al., 1978).
Attachment, Affection, Dependency, and Caregiving
An attachment relationship has a distinct organization. A child may enjoy a caregiver, receive food from a caregiver, prefer someone for play, or comply with an adult without those single observations establishing the attachment relationship's protective function. Conversely, vigorous protest at separation, following, seeking proximity during uncertainty, and relief during reunion may be more directly informative about attachment activation. The book's conceptual achievement was to make these distinctions analytically useful. Attachment behavior must be interpreted in situ, across relationships and development, rather than treated as a universal checklist of visible acts.
The word dependency appears in historical debates, but the attachment concept changes the question. Dependence can denote a practical need for care, while attachment refers to a particular relationship-based regulatory organization. Greater apparent independence in a brief observation does not necessarily mean greater attachment security, and abundant proximity seeking does not by itself imply an insecure attachment. Such conclusions require validated observational protocols, knowledge of developmental stage, and relational context (Bowlby, 1969; Ainsworth et al., 1978).
Ontogeny: How a Selective Attachment Develops
From early social responses to discrimination
Volume I treats attachment development as a process involving initial social signals, increasing discrimination, repeated interaction, mobility, expectations, and the organization of behavior around familiar caregivers. Infants begin life with perceptual and communicative capacities relevant to social contact, while the selective bond develops through maturation and experience. A developmental account must separate the emergence of smiling, orienting, recognition, stranger wariness, and directed proximity behavior; the forms and timing of their emergence vary across infants and settings. The book's sequential analysis matters because its theory predicts changing organization rather than one invariant behavior at every age (Bowlby, 1969).
The direct observational literature was essential to testing the breadth of these claims. Schaffer and Emerson's study of early social attachments investigated relationships in infancy beyond a simple account in which feeding alone determines whom the baby becomes attached to. This investigation also matters historically because it contributes to recognition of multiple attachments and variation in their emergence (Schaffer and Emerson, 1964).
Repeated interactions and expectations
As the child experiences a caregiver returning, comforting, noticing signals, or being unavailable, the relationship gains predictive structure. Bowlby's framework opened a path toward ideas about representations and expectations of the attachment figure and the self. The development of internal working models drew on a wider intellectual history, including Kenneth Craik's work on mental models. Discussions of their mature formulation frequently cite the 1982 revision and subsequent attachment scholarship; the exact historical stage of the argument must be tied to the edition under discussion. It would misrepresent the book to treat today's self-report attachment scales or modern adult attachment categories as if they were instruments devised in 1969 (Bowlby, 1982; Bretherton, 1992).
Mary Ainsworth's Distinct Research Contribution
Mary Dinsmore Salter Ainsworth was a major intellectual collaborator whose observational work changed attachment research from theoretical explanation into a program with operational measures. Her Uganda observations and Baltimore studies examined everyday caregiving, infant exploration, responses to separation and reunion, and individual differences in relationships. The Strange Situation procedure and the initial classifications based on its structured observations belong to this empirical research tradition. Their later elaboration, and the later disorganized classification associated with Mary Main and Judith Solomon, must not be attributed retrospectively to Bowlby as elements of the first edition (Bretherton, 1992; Ainsworth et al., 1978).
Ainsworth's findings were important precisely because the theoretical distinction between exploration and contact seeking could be investigated in observed dyads. The meaning of an observed behavior depends on the sequence of events, the caregiver's behavior, the infant's age, and the assessment method. Patterns of Attachment, published in 1978, presented the research design and methods associated with the Baltimore work; it is a separate original work from Bowlby's 1969 volume. The two sources should therefore be read as complementary contributions with different epistemic roles: one principally develops a theory, while the other presents methods and evidence for investigating individual differences.
Evidence in the 1969 Argument: What Its Sources Could Establish
The first volume assembled different kinds of evidence that do different scientific jobs. Child observations helped define behaviors and developmental phenomena. Reports of separation and reunion, including clinical and hospital contexts that informed Bowlby's work, revealed potential consequences of disrupted care and pointed to questions requiring explanation. Animal research supported comparison and generated hypotheses about adaptive organization. Psychoanalytic case interpretation identified problems and suggested psychological mechanisms. Feedback models connected observations in a unifying conceptual scheme. None of these sources alone could establish that a given early experience must produce a particular adult psychiatric outcome.
Clinical separation cases also raise familiar methodological problems: selection into treatment or institutional care, differences in prior family adversity, unmeasured illness, socioeconomic circumstances, preexisting development, variation in caregiving environments, and retrospective interpretation. Historical observations were productive in generating hypotheses, but later prospective, longitudinal, experimental, and meta-analytic research is necessary to evaluate claims about typical development or causal risk. Bowlby's 1982 retrospective reflects on the accumulation of evidence and on the theory's historical construction.
The 1982 Reassessment and the Growth of Attachment Science
Bowlby's second edition followed a period of intensified research on attachment processes and individual differences. Its new chapters and revisions matter because they show that the first volume was not treated as an unchangeable doctrine. The 1969 claim that attachment seeking can be understood as an organized protective system became the basis for questions about caregiver sensitivity, the organization of secure-base behavior, the development of expectations, and the predictive meaning of early patterns. These questions were subsequently addressed using methods not yet available in the original volume (Bowlby, 1982; Groh et al., 2017).
The breadth of the research tradition is important for another reason. Findings that support some basic principles do not endorse every historical detail. Attachment security, caregiver responsiveness, continuity, developmental outcomes, and attachment representations are distinct constructs with different measures and evidence. Each requires its own inquiry. A 1969 evolutionary rationale can remain historically influential even where particular predictions are revised, qualified, or remain insufficiently tested.
Contemporary Empirical Evaluation
Sensitive caregiving and attachment security
A 2024 meta-analysis by Madigan and colleagues pooled 174 samples, 230 effect sizes, and 22,914 child-caregiver dyads. It found a positive average association between caregiver sensitivity and child attachment security, r = .25, with a 95% confidence interval of .22 to .28. Associations involving maternal sensitivity and paternal sensitivity were both positive; the analysis did not support treating a father's responsive caregiving as scientifically irrelevant to security. The result supports a central developmental expectation of attachment research while documenting substantial variation among studies and a moderate, probabilistic association rather than a deterministic law (Madigan et al., 2024).
This contemporary result neither measures everything Bowlby meant by a protective attachment system nor verifies each historical suggestion about one primary figure. It addresses measured caregiver behavior and assessed attachment security in particular research designs. It is most informative when read alongside information on sample characteristics, reliability, observation length, and the assessment procedure, all of which affect observed associations.
Intervention and questions of causality
Correlations between caregiving and attachment cannot alone determine causal direction or eliminate unmeasured common causes. Interventions provide an additional source of evidence. A 2003 meta-analysis of early sensitivity and attachment interventions reported that randomized interventions showed average improvements in observed parental sensitivity and reductions in attachment insecurity, with more focused interventions often proving effective. Such research supports the possibility of changing some relationship processes, while its effect sizes and intervention conditions limit claims about any individual family (Bakermans-Kranenburg et al., 2003).
Temperament and relationship organization
One historical objection to attachment classifications is that they might largely reflect the infant's temperament instead of an emerging relationship. The two are neither equivalent nor wholly unrelated. A 2017 meta-analytic review based on 109 independent samples and 11,440 children reported a weak average association between temperament and attachment security, with variation by particular attachment classifications. This evidence lends qualified support to the importance of relational processes and cautions against ignoring temperament or measurement choices (Groh et al., 2017).
Longitudinal adaptation and risk
Evidence also supports some associations between early attachment and later socioemotional development, generally with modest average magnitudes and substantial heterogeneity. A meta-analysis of children's externalizing behavior reported an association between insecure attachment and externalizing problems across 69 samples (N = 5,947; d = .31), alongside stronger associations for some methods and samples. Such an estimate describes an average population-level relationship; it cannot diagnose a child, forecast an individual's adult life, or establish that a single early separation causes psychopathology (Fearon et al., 2010).
A broader synthesis of attachment in the early life course judged several developmental associations consistent with attachment theory while emphasizing unanswered questions about mechanisms, measurement models, replication, and the strength of predictive claims (Groh et al., 2017). That combination of support and revision is characteristic of an active scientific program. The durable contribution of Volume I is the organization of research questions, not a guarantee that attachment histories determine fixed destinies.
Scientific Criticism and Limits of the Original Volume
Maternal language and multiple attachment figures
The 1969 subtitle and much of the original vocabulary take the mother-child relationship as the primary example. Contemporary research treats attachment as a relationship that can develop with multiple reliably available caregivers and recognizes variation in family structure, cultural arrangements, and everyday care. Bowlby's account of preferred figures and the historical monotropy hypothesis must be read in that setting. Evidence that children discriminate among familiar people does not imply that only one woman can provide protection, and it does not justify assigning all responsibility for a child's development to mothers. Schaffer and Emerson's early observations and later meta-analytic findings involving fathers are relevant counterweights to an exclusively maternal interpretation (Schaffer and Emerson, 1964; Madigan et al., 2024).
Evolutionary hypotheses and testability
The book's evolutionary argument gave theoretical unity to behaviors that earlier traditions explained separately. Such explanations face the challenge of specifying predictions that distinguish a proposed adaptive history from other plausible developmental, social, or learning mechanisms. Evidence that children seek familiar protective people is compatible with Bowlby's functional interpretation but does not by itself establish the exact evolutionary pathway through which the behavior emerged. Different parts of an evolutionary hypothesis may have different evidentiary status; the book's historical importance should be retained without inflating that status.
Culture, socioeconomic conditions, and the ecology of care
Attachment behavior is embedded in living arrangements, caregiving networks, routines, illness, labor conditions, and social expectations. The observable form of proximity seeking and exploration varies with context. A single laboratory procedure or family norm cannot represent all cultural arrangements. Contemporary research therefore needs diverse samples, culturally informed interpretation, and attention to measurement equivalence. These requirements do not make protection and caregiving irrelevant; they make scientific claims about them more precise. The 1969 mother-centered examples should be read as examples from a particular historical research context rather than universal prescriptions.
Historical observations, mechanisms, and diagnosis
Bowlby's use of separation experiences as a source of theoretical questions cannot be turned into a modern diagnostic manual. An attachment classification is an assessment of an infant-caregiver relationship under specified conditions; it is not a psychiatric diagnosis. Common protest, fear, and proximity seeking in development do not, by themselves, establish separation anxiety disorder. Similarly, an insecure attachment classification is not a diagnosis of trauma, personality disorder, or an inevitable outcome. The theoretical book and contemporary clinical categories have distinct purposes, measures, and evidentiary thresholds (Fearon et al., 2010; Groh et al., 2017).
Intellectual Legacy of Volume I
The contribution of Attachment is the construction of a coherent explanatory system around the child's active role in seeking safety, the relational conditions that regulate exploration, and the development of selective bonds. Its influence can be traced in developmental observation, theories of emotion regulation, family research, infant mental health, and a variety of longitudinal approaches. It also shifted the history of psychological explanation by treating actual relational experience as a subject for prospective empirical inquiry. Bretherton's account of Bowlby and Ainsworth places this transformation within a collaborative intellectual history, while Bowlby's later retrospective shows how he understood the evolution of his ideas (Bretherton, 1992; Bowlby, 1982).
The book remains essential for understanding how attachment became a research program. Its continued value lies in the questions it made tractable and in the theoretical distinctions that later investigators were able to study. Current attachment research has its own experimental designs, measurement controversies, quantitative syntheses, and competing explanations. Reading the original volume alongside that evidence reveals both the explanatory ambition of Bowlby's work and the scientific development of the field after 1969.
Frequently Asked Questions
What is the principal argument of Attachment and Loss, Volume I?
Bowlby argues that a child's attachment to familiar protective people can be explained as a developing behavioral system with a function of maintaining or restoring access to safety. Its constituent behaviors are coordinated according to circumstances, learning, maturation, and the caregiver's availability. This is the central subject of the first volume, rather than a detailed theory of bereavement (Bowlby, 1969).
Was the first volume published in 1969 or 1982?
The original edition was published in 1969. A substantially revised second edition appeared in 1982, incorporating two new chapters. Both dates can therefore be correct when their corresponding editions are identified. Arguments involving wording or chapter placement should cite the edition actually consulted (Bowlby, 1969; Bowlby, 1982).
Did Bowlby create the Strange Situation procedure in this book?
No. Mary Ainsworth's research program developed the observational approach associated with the Strange Situation and secure-base assessment. Her empirical work informed the intellectual development of attachment theory, and the later publication Patterns of Attachment presents a separate methodological and evidentiary contribution (Ainsworth et al., 1978; Bretherton, 1992).
Does the volume prove that all children need one exclusive mother figure?
Its historical discussion focuses heavily on the mother and on preferred attachment figures. Modern research includes multiple caregiving relationships and documents associations between child attachment security and both maternal and paternal sensitivity. The book should be situated in its historical context rather than converted into a universal rule about a single required caregiver (Madigan et al., 2024).
Is attachment security a permanent personality type?
Attachment security is a construct assessed in particular relationships and contexts. Later outcomes reflect multiple processes, and observed associations are probabilistic. The first volume establishes a developmental framework rather than a lifelong, immutable taxonomy for every person. Contemporary meta-analytic findings support this more qualified interpretation (Groh et al., 2017).
Related Articles
John Bowlby — A full scientific account of Bowlby's life, intellectual formation, original works, and wider legacy.
Attachment in Infancy and Early Childhood: Security and Development — Contemporary evidence on the developing attachment relationship, observed security, and caregiving.
Is Attachment Theory Evidence-Based? What Research Supports, What It Does Not, and Common Misuses — A separate appraisal of the broader scientific research tradition and evidentiary boundaries.
Sigmund Freud — The psychoanalytic historical context from which Bowlby's alternative formulation emerged.
John Bowlby's Attachment and Loss Trilogy — An integrated guide to Bowlby's three-volume project.
John Bowlby's Attachment Behavioral System and Ethology — The ethological and regulatory foundation of attachment behavior.
References
Ainsworth, M. D. S., Blehar, M. C., Waters, E., and Wall, S. (1978). Patterns of attachment: A psychological study of the Strange Situation. Lawrence Erlbaum Associates. Publisher and bibliographic record.
Bakermans-Kranenburg, M. J., van IJzendoorn, M. H., and Juffer, F. (2003). Less is more: Meta-analyses of sensitivity and attachment interventions in early childhood. Psychological Bulletin, 129(2), 195–215. https://doi.org/10.1037/0033-2909.129.2.195.
Bowlby, J. (1958). The nature of the child's tie to his mother. International Journal of Psycho-Analysis, 39, 350–373. https://pubmed.ncbi.nlm.nih.gov/13610508/.
Bowlby, J. (1969). Attachment and loss. Vol. 1: Attachment (1st ed.). Basic Books / Hogarth Press and the Institute of Psycho-Analysis. 1969 bibliographic record.
Bowlby, J. (1982a). Attachment and loss. Vol. 1: Attachment (2nd ed.). Basic Books. Publisher edition bibliographic record.
Bowlby, J. (1982b). Attachment and loss: Retrospect and prospect. American Journal of Orthopsychiatry, 52(4), 664–678. https://doi.org/10.1111/j.1939-0025.1982.tb01456.x.
Bretherton, I. (1992). The origins of attachment theory: John Bowlby and Mary Ainsworth. Developmental Psychology, 28(5), 759–775. https://doi.org/10.1037/0012-1649.28.5.759.
Fearon, R. M. P., Bakermans-Kranenburg, M. J., van IJzendoorn, M. H., Lapsley, A.-M., and Roisman, G. I. (2010). The significance of insecure attachment and disorganization in the development of children's externalizing behavior: A meta-analytic study. Child Development, 81(2), 435–456. https://doi.org/10.1111/j.1467-8624.2009.01405.x.
Groh, A. M., Fearon, R. M. P., van IJzendoorn, M. H., Bakermans-Kranenburg, M. J., and Roisman, G. I. (2017a). Attachment in the early life course: Meta-analytic evidence for its role in socioemotional development. Child Development Perspectives, 11(1), 70–76. https://doi.org/10.1111/cdep.12213.
Groh, A. M., Narayan, A. J., Bakermans-Kranenburg, M. J., Roisman, G. I., Vaughn, B. E., Fearon, R. M. P., and van IJzendoorn, M. H. (2017b). Attachment and temperament in the early life course: A meta-analytic review. Child Development, 88(3), 770–795. https://doi.org/10.1111/cdev.12677.
Madigan, S., Deneault, A.-A., Duschinsky, R., Bakermans-Kranenburg, M. J., Schuengel, C., van IJzendoorn, M. H., Ly, A., Fearon, R. M. P., Eirich, R., and Verhage, M. L. (2024). Maternal and paternal sensitivity: Key determinants of child attachment security examined through meta-analysis. Psychological Bulletin, 150(7), 839–872. https://doi.org/10.1037/bul0000433.
Schaffer, H. R., and Emerson, P. E. (1964). The development of social attachments in infancy. Monographs of the Society for Research in Child Development, 29(3), 1–77. https://pubmed.ncbi.nlm.nih.gov/14151332/.