There's 2nd-circle enhancement spells for all three of them, granting to each trait a +4 bonus as measured by the corresponding spell, lasting for 2 minutes per caster circle. Clerics can cast enhancement of 'Wisdom' and 'Splendour', wizards can enhance all three.
Sorcerers cast wizard spells but intuitively, without study, through will alone; 'Splendour' is to them what 'Intelligence' is to wizards.