A weakness of Bowlby's maternal deprivation hypothesis?

-Poor quality of evidence that it is based on -Bowlby's 44 thieves study was flawed because Bowlby was the one who carried out both the interview and assessments of affectionless psychopathy. Let him to be biassed because he knew in advance which teenagers he expected to show signs of psychopathy. -Other sources of evidence were flawed, Bowlby was influenced of the findings of Glodfarb's reserach of development of deprived children in wartime orphanages. This research had confounding variables as the children had experience prolonged trauma and institutional care as well was prolonged separation from their primary caregivers -Means that Bowlby's original sources of evidence for maternal deprivation had serious flaws and would not be taken seriously as evidence nowadays