“The fact is that there’s no strong evidence for parent–child attachment in infancy predicting anything much about children’s later development. Indeed, Booth-LaForce and Roisman’s definitive 2014 study showed that early attachment doesn’t even predict attachment later in development, let alone all of these other things.”
Nice, concise, critical analysis of attachment claims, by Elizabeth Meins (2016).
A court case (GM v Carmarthenshire County Council  EWFC 36) has ruled that a social worker’s “generalised statements, or tropes” based on attachment theory are not admissible evidence.
The full judgement by Mr Justice Mostyn has interesting thoughts on the valid application of theory and balance between theory and observation.
“… the local authority’s evidence in opposition to the mother’s application was contained in an extremely long, 44-page, witness statement made by the social worker […]. This witness statement was very long on rhetoric and generalised criticism but very short indeed on any concrete examples of where and how the mother’s parenting had been deficient. Indeed, it was very hard to pin down within the swathes of text what exactly was being said against the mother. […] [The social worker] was asked to identify her best example of the mother failing to meet L’s emotional needs. Her response was that until prompted by the local authority mother had not spent sufficient one-to-one time with L and had failed on one occasion to take him out for an ice cream. […] A further criticism in this vein was that the mother had failed to arrange for L’s hair to be cut in the way that he liked.”
There is also a detailed section on attachment theory:
“… the theory is only a theory. It might be regarded as a statement of the obvious, namely that primate infants develop attachments to familiar caregivers as a result of evolutionary pressures, since attachment behaviour would facilitate the infant’s survival in the face of dangers such as predation or exposure to the elements. Certainly, this was the view of John Bowlby, the psychologist, psychiatrist, and psychoanalyst and originator of the theory in the 1960s. It might be thought to be obvious that the better the quality of the care given by the primary caregiver the better the chance of the recipient of that care forming stable relationships later in life. However, it must also be recognised that some people who have received highly abusive care in childhood have developed into completely well-adjusted adults. Further, the central premise of the theory – that quality attachments depend on quality care from a primary caregiver – begins to fall down when you consider that plenty of children are brought up collectively (whether in a boarding school, a kibbutz or a village in Africa) and yet develop into perfectly normal and well-adjusted adults.”
Much to discuss!