Thinking too much: self-generated thought as the engine of neuroticism

• Existing neuroticism models cannot explain its link to both unhappiness and creativity.
• Self-generated thought (SGT) facilitates creativity but can cause unhappiness.
• Threat-related regions of medial prefrontal cortex (mPFC) generate blue-tinted SGT.
• High neuroticism may reflect proneness to SGT arising from mPFC hyperactivity.

Neuroticism is a dimension of personality that captures trait individual differences in the tendency to experience negative thoughts and feelings. Established theories explain neuroticism in terms of threat sensitivity, but have limited heuristic value since they cannot account for features of neuroticism that are unrelated to threat, such as creativity and negative psychological states experienced in benign, threat-free environments. We address this issue by proposing that neuroticism stems from trait individual differences in activity in brain circuits that govern the nature of self-generated thought (SGT). We argue our theory explains not only the association of neuroticism with threat sensitivity but also the prominence within the neurotic mind of representations of information that are unrelated to the way the world is right now, such as creativity and nonsituational ‘angst’.