Introduction to Psychology 101

Cognitive Development

Piaget proposed that children move through four stages of mental development.

1. Sensorimotor Stage (Birth to 2 years)

The infant knows the world through movements and sensations. Object Permanence (knowing something exists even if you can't see it) is learned here.

2. Preoperational Stage (2 to 7 years)

Children begin to think symbolically but remain egocentric (cannot see others' perspectives).

3. Concrete Operational (7 to 11)

Logical thought begins. Understanding of Conservation (water in a tall glass is the same amount as in a short glass).

Qualitative vs. Quantitative

• Quantitative: Deals with numbers and statistics (Surveys, Correlation studies). Easier to replicate.
• Qualitative: Deals with descriptions and meanings (Case studies, Interviews). Richer detail but harder to generalize.