The ability to understand and to incorporate the rules of basic logical inference in everyday activities.

Regarded as a universal human trait, the ability to think logically, following the rules of logical inference, has traditionally been defined as a higher cognitive skill. The field of cognitive child psychology was dominated for more than half a century by the Swiss philosopher and psychologist Jean Piaget, whose studies are considered fundamental. Piaget identified four stages of cognitive development. During the sensory-motor stage (ages 0-2), the child learns to experience the world physically and attains a rudimentary grasp of symbols. In the...