An investigation of difficult temperament
: developmental pathways to later-life outcomes

Student thesis: Doctoral ThesisDoctor of Philosophy


Accumulating evidence suggests that difficult temperament emerging early in life shows consistent associations with problems in mental health and social functioning much later in the life course. However, few studies have examined how an overall factor (as opposed to specific dimensions) of difficult temperament associates with these developmental outcomes, as well as testing underlying mechanisms. In three empirical studies, the current thesis aimed to build on existing research by examining the long-term implications of one particular model of difficult temperament for functioning later in development, and exploring a range of potential mediating and moderating mechanisms.

The thesis consists of six chapters. Chapter 1 provides the overall theoretical background, by introducing the current research on difficult temperament and various developmental outcomes. Chapter 2 describes the analytic sample and statistical methods used in the present thesis. The three empirical studies conducted are described in Chapters 3, 4, and 5. In Chapter 3, three possible relationships (direct, mediated, and moderated-mediated) between an overall difficult temperament in toddlerhood and mental health outcomes (i.e. depression and well-being) in young adulthood were tested. More difficult temperament was found to be associated directly with worse mental health outcomes, and indirectly via associations with higher levels of a general psychopathology factor in late childhood/early adolescence. No evidence of moderation by parenting was found. In Chapter 4, the relationship between difficult temperament and NEET status (i.e. not in education, employment, or training) in young adulthood was examined. Difficult temperament was associated with increased risks for being NEET, and this effect also occurred via indicators of difficulties in emotional and behavioural self-regulation, such as ADHD and antisocial behaviours. In Chapter 5, the item-level associations between aspects of difficult temperament and peer victimisation, as well as the moderating role of genetic risks, were tested using network analysis. Aspects of difficult temperament were associated with peer victimisation, and these associations were moderated by one’s genetic risks. Chapter 6 includes a summary and discussion on the main findings from the empirical studies, as well as limitations and future directions for research.

Overall, the current findings provided further insight into the mechanisms through which difficult temperament emerging early in life associates with outcomes later in development.
Date of Award1 Oct 2022
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorEdward Barker (Supervisor) & Barbara Maughan (Supervisor)

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