In which theory the age-related changes in intelligence are best explained? Cattell's theory

In which theory the age-related changes in intelligence are best explained? Cattell's theory

کس نظریے میں ذہانت میں عمر سے متعلق تبدیلیوں کی بہترین وضاحت کی گئی ہے کیٹیل کے نظریے
Explanation

 In which theory the age-related changes in intelligence are best explained Cattell's theory