The development of an attachment is a complex process. Through the process, some children develop secure, trusting bonds – while others do not. According to attachment theory, the behavior of caregivers can influence this process positively or detrimentally, depending on their actions and the situation.
What is attachment theory?
The central idea of attachment theory is that humans are born with a biological drive to develop a deep emotional bond with their caregiver – a bond that extends beyond having basic physical needs met.
The security of our early relationships can go on to influence our psychological wellbeing and relationships later in life. Children who do not have close, secure emotional bonds are more likely to go on to experience difficulties in the future.
Stages of attachment in childhood
According to attachment theory, there are four stages of forming an attachment between a child and their caregiver:
- Pre-attachment: Newborn infants naturally do things that attract the attention of their caregivers, such as crying. They are soothed and comforted by their caregivers but do not yet show a preference for being soothed by them specifically.
- Indiscriminate attachment: From around 6 weeks, infants develop a closer bond with their caregiver, and show a preference for being soothed by them over others. They engage in more behaviors that attract their caregiver’s attention and can be soothed by them more quickly.
- Discriminate attachment: From around 7 months, there is a strong and preferential attachment to the child's caregiver. The child may become upset when separated from this primary attachment figure.
- Multiple attachments: From around 18 months onwards, the child forms attachments with more than one person. As the child develops language and communication skills they develop an internal sense of security. This means that, for example, they begin to understand that if their caregiver leaves, that they will return. They become aware that their caregiver is supporting them even when they are not physically present.
Children tend to develop a particular style of attachment to their caregiver. Attachment styles include:
- Secure attachment: The ideal form of attachment established between the child and their caregiver. The child develops the understanding that their caregiver is there for them and supportive of them. They have developed a secure and trusting emotional bond. They have the confidence to explore their surroundings, knowing that they have the secure base of their caregiver to return to for support.
- Anxious-avoidant insecure attachment: In this style of attachment, the trusting and secure relationship between child and caregiver has not been established. The child is anxious and does not trust that their caregiver will meet their needs. They react less to the physical presence or absence of their caregiver and tend to explore less.
- Anxious-ambivalent insecure attachment: Again, in this style of attachment, the trusting and secure relationship between child and caregiver has not been established, and the child does not trust that their caregiver will meet their needs. They are likely to display more emotion than the avoidant style of attachment. For example, they are likely to become quite distressed when separated from their caregiver.
This aspect of attachment theory is grounded in the research of developmental psychologist, Mary Ainsworth. Later developments in attachment theory led to a general consensus that these early attachments can go on to influence relationships in adulthood. 
How is attachment theory important to therapy?
It is thought that early attachments can continue to influence us in adulthood, affecting how we:
- Regulate our emotions
- Solve problems
- Behave in relationships
- Cope more broadly
For example, research shows that an insecure attachment can impact on our later experiences of depression and anxiety, as well as our attitudes and self-esteem.  As such, attachment theory is relevant to how mental health professionals provide therapy today.
Therapists might draw on attachment theory to understand a person’s maladaptive coping strategies and any underlying needs and teach more adaptive coping strategies. Some types of therapy are specifically based on the theory, such as:
- Emotionally Focused Couples Therapy (EFCT), for example, is a well established and researched way of helping couples who are experiencing relationship problems. It aims to help couples develop the trusting and secure bond that is considered to be of utmost importance in attachment theory.
- Accelerated Experiential Dynamic Psychotherapy (AEDP) is another example of a therapeutic approach based in attachment theory.