From the moment a baby is born, relationships begin to matter. A newborn depends on adults for food, warmth, protection and comfort, but the relationship between a baby and their caregiver involves much more than meeting physical needs. Over time, babies develop emotional bonds with the people who care for them, and psychologists have spent decades studying how these early relationships develop and what they might mean for later life.
This area of psychology is known as attachment. Attachment helps explain why babies become upset when a familiar caregiver leaves, why they may prefer certain people when they are frightened, and why they often seek comfort from a particular caregiver when they feel distressed.
But how does attachment develop? Do babies become attached to anyone who feeds them, or is there something more complicated happening? And can the quality of early attachment affect relationships later in life?
What is attachment?
An attachment is a strong emotional bond between two people. In developmental psychology, the term is often used to describe the emotional relationship that develops between an infant and their caregiver.
A securely attached baby may use their caregiver as a secure base. They feel confident enough to explore their surroundings when the caregiver is nearby, but they return to the caregiver when they feel frightened or uncertain.
For example, imagine a young child playing in a new room. They may move away from their parent to explore some toys, but occasionally look back to make sure the parent is still there. If something scares them, they may run back for comfort. Once they feel safe again, they may return to exploring.
This balance between exploration and seeking comfort is an important feature of attachment.
How does attachment develop?
Psychologists have proposed different explanations for how attachments develop.
One early explanation came from learning theory. Behaviourists suggested that babies may become attached to caregivers because caregivers provide things the baby needs, particularly food.
From this perspective, feeding is important because it provides a primary reinforcer: food reduces hunger. The caregiver becomes associated with this rewarding experience, and attachment develops through conditioning.
However, later research suggested that attachment cannot simply be explained by feeding.
One of the most important studies was carried out by Harry Harlow using rhesus monkeys.
Harlow's monkey study
Harlow wanted to investigate whether infant monkeys were attached to their mothers primarily because mothers provided food or because of the comfort and security they provided.
Baby monkeys were separated from their biological mothers and given access to two artificial surrogate mothers. One was made from wire and provided milk. The other was covered in soft cloth but did not provide food.
If attachment were primarily about feeding, we might expect the monkeys to spend most of their time with the wire mother. Instead, the monkeys generally spent much more time clinging to the soft cloth mother, particularly when they were frightened. This suggested that contact comfort was an important factor in attachment.
Harlow's findings challenged the idea that attachment develops simply because a caregiver provides food. The emotional and comforting qualities of the relationship appeared to be important as well.
However, the study is also controversial because of the distress experienced by the animals and the ethical concerns surrounding the procedures. It is therefore important to consider both what the research demonstrated and the ethical issues involved.
Bowlby's theory of attachment
Another major psychologist in the study of attachment was John Bowlby.
Bowlby argued that attachment has an important biological and evolutionary function. He suggested that babies are born with behaviours designed to encourage adults to care for them.
For example, babies cry, smile and make sounds that attract adult attention. These behaviours can encourage caregivers to remain close to them. From an evolutionary perspective, staying close to a protective caregiver would have increased an infant's chances of survival.
Bowlby therefore described attachment as monotropic, meaning that infants have a particular tendency to form one especially strong attachment. He believed that this primary attachment was particularly important and that other relationships developed around it.
The critical period
Bowlby also proposed the idea of a critical period for attachment. He suggested that there is an important period during early childhood during which attachments are most likely to develop. Bowlby originally suggested that this period was roughly the first two and a half years of life, with attachment becoming increasingly difficult to establish after this time.
This idea has been influential, but later research has suggested that attachment development is more flexible than Bowlby's original description implied.
Rather than thinking of attachment as something that either happens within a strict deadline or never happens, psychologists now recognise that development can be more complicated.
The strange situation
One of the most famous studies of attachment was conducted by Mary Ainsworth and her colleagues.
Ainsworth developed a procedure known as the Strange Situation to investigate how infants respond to separation from and reunion with their caregivers.
The procedure involved an infant, their caregiver and a stranger in an unfamiliar environment. The caregiver would leave the room for a short period and then return.
Researchers observed several behaviours, including how the child explored the environment, how they responded when the caregiver left, how they reacted to the stranger and, importantly, how they behaved when the caregiver returned.
The Strange Situation led Ainsworth to identify different patterns of attachment.
Secure attachment
Children classified as securely attached generally used their caregiver as a secure base from which to explore. They might become upset when their caregiver left, but they were usually comforted when the caregiver returned. After receiving comfort, they could return to exploring their surroundings.
Secure attachment is therefore characterised by a balance between independence and seeking reassurance.
Insecure-avoidant attachment
Children with an insecure-avoidant attachment pattern tended to show relatively little distress when their caregiver left and could appear relatively independent when the caregiver returned. They might avoid or ignore the caregiver after separation.
This does not necessarily mean that the child has no emotional response. Their outward behaviour may not fully reveal what they are experiencing internally.
Insecure-resistant attachment
Children with an insecure-resistant or ambivalent attachment pattern tended to become highly distressed when their caregiver left but were not easily comforted when the caregiver returned.
They might seek contact while simultaneously resisting it, for example by reaching towards the caregiver but then pushing them away. This can make their behaviour appear inconsistent.
What does attachment tell us about later life?
One of the most interesting questions is whether early attachment influences relationships later in life.
Bowlby's theory suggested that early relationships could contribute to an internal working model. An internal working model is essentially a mental framework that helps a person understand relationships and what they can expect from other people.
For example, a child who experiences consistent care may develop expectations that other people can be trusted and that relationships can provide support whereas a child who experiences inconsistent or unreliable care may develop different expectations.
This does not mean that childhood completely determines a person's future. Human development is much more complicated than that. Later relationships and experiences can also influence how people think about themselves and others.
Maternal deprivation
Bowlby also investigated the possible effects of being separated from a primary caregiver. He argued that prolonged separation during early childhood could have serious consequences for emotional development, particularly if the child lacked a suitable substitute caregiver.
This became known as the maternal deprivation hypothesis.
Bowlby suggested that prolonged deprivation could potentially lead to difficulties with emotional development and later relationships.
His ideas had a major influence on childcare practices, although later researchers have challenged some aspects of his theory and argued that the effects of separation depend on factors such as the length of separation, the child's age and the quality of alternative care.
Is attachment determined entirely by parents?
The answer here is No.
This is an important point when studying attachment. Attachment research does not mean that every aspect of a person's personality or future relationships can be blamed on their parents.
Children develop within complex environments. Their experiences can include relationships with parents, grandparents, siblings, teachers, friends and other caregivers.
Temperament can also play a role. Some children may naturally be more cautious, sociable or emotionally reactive than others.
Social and cultural factors can influence caregiving practices as well.
This is why psychologists must be careful when interpreting attachment research. A relationship between early experiences and later behaviour does not automatically prove that one directly caused the other.
Why is attachment important?
Attachment research helps psychologists understand early emotional development and the importance of relationships during childhood. It also has practical applications. Understanding attachment can help parents, teachers, childcare professionals and social workers think about how children respond to separation, unfamiliar environments and changes in caregiving.
For students studying psychology, attachment is also an excellent example of how psychologists use observations, experiments and theories to investigate human behaviour.
Research such as Harlow's work and Ainsworth's Strange Situation provides evidence that can be used to support or challenge psychological explanations.
Final thought
Attachment reminds us that human development is not simply about physical growth. From the earliest stages of life, relationships can influence how children experience safety, comfort and the world around them.
Research by psychologists such as Bowlby, Ainsworth and Harlow has helped us understand why infants seek particular caregivers, how they respond to separation and how early relationships may influence later development.
At the same time, attachment research also teaches us to avoid simple conclusions. Early experiences matter, but they are only one part of a much larger developmental story.
Our relationships continue to change throughout life, and later experiences can shape the way we understand ourselves and other people.
That is what makes attachment such an important area of psychology: it begins with a baby's need for comfort and security, but it raises much bigger questions about how relationships shape human development.