Intelligence/personality associations were studied in four large datasets. Correlations between general ability (g) and major personality traits were generally consistent with previous findings. For other traits, an interpretation of the correlation patterning is that traits classifiable as adaptive in terms of personal and social adjustment have positive correlations with g, whilst maladaptive traits have negative correlations. Regression modelling confirmed these associations and structural equation modelling of selected traits showed that Neuroticism acts as a mediator of g on the outcome. Non-linear relationships between intelligence and personality were not found. In two of the datasets the correlation between Neuroticism and Psychoticism decreased with ability level, and the correlation between fluid and crystallised ability increased with level of Neuroticism.