Overview
- A composite of 16 cognitive and personality dimensions shows overall functioning peaking at 55–60, with average declines beginning near 65 and accelerating after about 75.
- Conscientiousness peaks around 65 and emotional stability around 75, while moral reasoning and resistance to cognitive biases can keep improving into the 70s and 80s.
- Researchers pooled and standardized large studies covering reasoning, memory span, processing speed, knowledge, emotional intelligence, and the Big Five traits to map lifespan trajectories.
- The authors say midlife strengths help explain the prevalence of leaders in their 50s and early 60s and recommend age‑inclusive hiring based on individual assessments rather than assumptions.
- Led by Gilles Gignac (University of Western Australia) and Marcin Zajenkowski (University of Warsaw), the work in Intelligence aligns with evidence that fluid abilities peak early while crystallized knowledge grows into later life.