IB Psychology HLTopic 2 — Development of the SelfPaper 1 & 2Core theory~11 min read
Bowlby and the Roots of Attachment
A human baby is born unable to feed itself, move itself or protect itself. Bowlby’s answer to that problem is the whole theory: babies come with a built-in system for getting an adult to stay close and care for them. Attachment is not affection. It is survival equipment.
📘 What you need to know
John Bowlby (1907–1990) argued attachment is an innate system shaped by evolution to promote survival.
Infants attach for protection, food and nurture; caregivers attach so that the infant survives.
The theory is monotropic: the child forms one special bond with a key caregiver, plus weaker ones with others.
Two principles of monotropy: the law of continuity and the law of accumulated separation.
Social releasers — smiling, cooing, gripping, the “cute” baby face — pull the caregiver in.
There is a critical period from around three to six months when attachment must form.
The internal working model is the template early attachment leaves behind for later relationships.
Ainsworth (1970) measured attachment styles using the Strange Situation.
Monotropy: one bond above the rest
Bowlby did not claim a baby loves only one person. He claimed the attachments are not equal — one relationship, the primary attachment figure, sits above the others and does most of the developmental work. That figure is usually the mother, but it can be a father, a grandparent, or anyone else who is consistently there.
The thick line is the claim being tested. Later research suggests children form several real attachments from around 10–11 months, which is where monotropy comes under pressure.
The two principles of monotropy
Law of continuity: the more constant and predictable the care, the better the quality of attachment.
Law of accumulated separation: every separation from the primary attachment figure has an effect, and they add up.
The word “accumulated” is doing real work in that second law. Bowlby is not saying one afternoon apart damages a child. He is saying the separations add together, like a bill that keeps running.
Social releasers and the critical period
A baby cannot ask for care, so evolution gave it something better: behaviours that make adults want to give care anyway. Bowlby called these social releasers.
smiling — almost impossible not to answer
cooing — pulls an adult into conversation before language exists
gripping a finger — contact that adults read as connection
the baby face — large eyes, button nose, round shape, rosy cheeks
The system runs both ways: the more responsive the caregiver, the stronger the attachment becomes. And Bowlby argued there is a critical period, roughly three to six months, when this must happen. If attachment is not formed in that window, forming attachments later is much harder.
The internal working model
The first relationship becomes a template. A child who receives loving, secure care from a consistent and safe caregiver grows up expecting that from relationships. A child whose primary relationship is negative tends to expect poor treatment later — and may treat others that way too.
Why the model matters for essays. The internal working model is the mechanism that turns an early experience into a lifelong pattern. Without it, Bowlby’s theory only explains babies. With it, it explains adults.
Key study: Ainsworth (1970), the Strange Situation
🧩 The study in four steps
Aim — to investigate attachment style in infants using the Strange Situation, drawing on Bowlby’s theory.
Participants — 56 white, middle-class infants from the USA, aged 49–51 weeks.
Procedure — a 20-minute controlled observation in an unfamiliar room with interesting toys. The mother and a stranger enter and leave in a set sequence: the stranger arrives and approaches the baby, the mother leaves and returns, the baby is left alone, the stranger returns, and finally the mother returns and picks the baby up. Observers recorded exploration, distress on separation, response to the stranger and behaviour on reunion.
Conclusion — attachment can be measured through observation. Most children are securely attached, but insecure patterns are linked to long-term effects.
Learn the two insecure types as a pair of opposites: Type A does not seem to care that mum left, Type C cares so much it cannot be soothed when she comes back.
Type
In the room
When mum leaves and returns
Later relationships
Type A: insecure-avoidant
Little interest in mother, unbothered by the stranger
Little distress at separation, little response at reunion
Detached, low intimacy, low empathy
Type B: secure
Uses mother as a secure base to explore, avoids the stranger
Distressed when she leaves, comforted by her return
Trust, openness, autonomy, healthy intimacy
Type C: insecure-resistant
Clingy, distressed even while mother is present
Extreme distress, then not easily comforted; mixed anger and anxiety
Insecure, jealous, needy, emotionally volatile
Evaluating Bowlby’s theory
Strengths
Animal studies support the innate claim. Lorenz (1935) found goslings imprint on the first moving object they see, which fits the idea that attachment is an inborn survival process rather than something learned.
Evidence for social releasers. When caregivers were instructed to ignore their baby’s crying or smiling, the babies became increasingly distressed — suggesting these behaviours really are used to pull attention and care from an adult.
Ainsworth gave the theory a method. The Strange Situation turned an abstract idea into something observable and classifiable.
Limitations
Multiple attachments. Research shows children form attachments to a range of caregivers from around 10–11 months, so monotropy may not be completely valid.
The critical period is not absolute. Some children have formed attachments after the three-to-six month window, so “sensitive period” is a fairer description.
Narrow sample. Ainsworth’s 56 infants were white, middle-class and American. Applying those percentages to every culture is a serious overreach.
Link to concepts
Measurement — attachment is difficult to operationalise. The Strange Situation uses clearly defined behavioural categories, but attachment is complex and may not be captured in one 20-minute session. It is also a snapshot taken on a single day, so it lacks temporal validity; a longitudinal design would test whether classifications stay stable.
Responsibility — research on real parent–child pairs is full of ethical issues. The child must experience some mild distress for the results to be valid, and a baby cannot be asked whether they want to withdraw. If a researcher suspects abuse they must report it — but they may also have misread what they saw, and a parent could be wrongly accused.
Exam practice
WORKED EXAMPLE
Outline one theory of attachment. [3 marks]
1. The core claim
Bowlby argued attachment is innate and evolved, because staying close to a caregiver keeps a helpless infant alive.
2. A key featureMonotropy: one primary attachment figure matters more than the rest.
3. The long-term mechanism
That relationship forms an internal working model, a template for later relationships.
Claim + feature + mechanismDo not spend the whole answer listing social releasers. They are a detail, not the theory.
WORKED EXAMPLE
Discuss ethical considerations in research on attachment. [ERQ paragraph]
Issue
The Strange Situation deliberately causes mild distress by separating a baby from its mother.
Why it is difficultThat distress is required for the measure to be valid — take it away and there is nothing to observe.
Second issue
An infant cannot understand or exercise the right to withdraw, so consent sits entirely with the parent.
Judgement
The design is defensible only because the distress is brief and controlled, but it shows validity and ethics can pull against each other.
Issue, tension, second issue, judgement“It was unethical” is not an argument. Show the trade-off.
💡 Exam tip
Spell out the evolutionary logic in one sentence — helpless infant, needs protection, so attachment is selected for. Examiners reward that link.
Use the type letters and the names. “Type B, secure” is safer than either alone.
Quote the sample details for Ainsworth. They are your ready-made generalisability criticism.
Lorenz is an animal study — strong support for innateness, weak for human complexity. Say both.
The internal working model is your bridge to any question about later relationships or adult behaviour.
Controlled observation, not experiment. There is no manipulated variable in the Strange Situation.
⚠️ Common mix-up
Monotropy does not mean one attachment only. It means one bond outranks the others.
Type A is not “no attachment”. It is an attachment pattern — an insecure one.
Do not swap A and C. A is avoidant and looks unbothered; C is resistant and cannot be soothed.
Attachment figure is not automatically “mother”. Bowlby allowed for a father, grandparent or other consistent carer.
Critical period is not proven. Attachments have formed later, so treat it as a claim under challenge.
Imprinting is not attachment. Lorenz’s goslings support the idea; they do not demonstrate human attachment.
Up next: What Happens When Attachment Is Missing — Bowlby’s theory predicts consequences when the bond is broken, and he tested that prediction on 44 young thieves.
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