Objective Measures or Subjective Measures? In this week’s blog, we take a look at the difference between objective and subjective measures in capturing the impact of early life trauma on mental health.
Psychological traumas are typically defined as experiences that cause actual or potential harm to an individual’s survival, health, or dignity. These include experiences such as physical maltreatment, emotional abuse, or bullying. Sadly, these experiences are most likely to occur early in life, with young people being exposed to higher rates of trauma than other age groups. Across healthcare and research, the terms used to describe these early life experiences can vary, but they are also commonly referred to as adverse childhood experiences (ACEs) or childhood maltreatment.
When traumas are experienced at an early age, they can have a huge impact on physical and mental wellbeing throughout life. Therefore, researchers need to understand the best ways to provide support for those who have experienced early life trauma. The first step is to identify those who may be at risk because of their early experiences. However, due to the sensitive nature of this topic, it is challenging to identify those who have experienced early life trauma.
Two types of measure can be used to assess early life experiences. Broadly, these can be defined as objective and subjective. Objective measures include records made by someone other than the individual themself, including researcher or parent reports, or official records such as court documents. These records tend to be from the time of the experience occurring, which is described as a ‘prospective’ measure.
In contrast, subjective measures are self-reported and assess personal narratives. When taken in childhood, self-reports can also capture traumas from the time of the experience occurring. However, these experiences are often not recorded until much later in life, resulting in ‘retrospective’ self-reports of past experiences.
The use of subjective measures of trauma has typically relied on the assumption that self-reports capture the same experiences that objective measures would detect. However, a review of reports from over 25,000 individuals has cast some doubt over this assumption, finding that the experiences identified from retrospective self-reports of early life trauma showed very little overlap with prospective records from early in life. More than half of individuals with prospective records of childhood maltreatment did not retrospectively self-report the experience later in life. Additionally, more than half of individuals who retrospectively reported childhood maltreatment did not have matching prospective records.
This finding is displayed in the figure below, taken from the paper by Baldwin, Reuben, Newbury & Danese (2019). The venn diagrams overlap between experiences identified by prospective records (dark circles) or retrospective reports (light circles). The smallest agreement between the two types of measures is seen for childhood physical abuse and emotional abuse. The largest agreement is for records of being separated from a parent, for example, due to divorce or death.
There may be several reasons why the overlap between the two types of measure is low. Motivation, embarrassment or access to information may influence the disclosing of experiences about someone else versus yourself, resulting in objective records and self-reports capturing different experiences. Additionally, official records might capture only the most severe cases of maltreatment, whereas self-reports might detect a bigger range of cases. Memory biases may also influence retrospective reports more than objective records. Finally, the definitions of maltreatment applied when assessing trauma in childhood compared to retrospectively in adulthood may be different. For example neglect may be identified prospectively as a lack of parental affection, but retrospectively as lack of input or stimulation.
Regardless of the reasons, this research indicates that objective and subjective measures of early life trauma may be capturing different experiences, and therefore it is advisable not to use them interchangeably. Crucially, these findings do not imply that one measure is ‘valid’ while the other is ‘invalid’, rather that we may need to use them for different purposes. Interestingly, some evidence suggests that subjective measures are more strongly associated with a risk of psychopathology in adulthood than objective measures. This emphasises just how important it is to understand the subject experience when assessing early life experiences.
Lewis, S. J., Arseneault, L., Caspi, A., Fisher, H. L., Matthews, T., Moffitt, T. E., Odgers, C. L., Stahl, D., Teng, J. Y., & Danese, A. (2019). The epidemiology of trauma and post-traumatic stress disorder in a representative cohort of young people in England and Wales. The Lancet Psychiatry, 6(3), 247–256.
Baldwin, J. R., Reuben, A., Newbury, J. B., & Danese, A. (2019). Agreement between prospective and retrospective measures of childhood maltreatment: a systematic review and meta-analysis. JAMA Psychiatry , 76(6), 584–593.
Baldwin, J. R., & Degli Esposti, M. (2021). Triangulating evidence on the role of perceived versus objective experiences of childhood adversity in psychopathology. JCPP Advances, 1(1), e12010.
Danese, A., & Widom, C. S. (2020). Objective and subjective experiences of child maltreatment and their relationships with psychopathology. Nature Human Behaviour, 4(8), 811-818.