Developmental Psychology:

The study of how people change physically, mentally, and socially throughout the lifespan.

One big issue:

Do we develop in age-related Stages – at certain ages we change quickly from one stage to another

Or do we experience Gradual Unfolding – we change a little bit every day, and change is only noticeable over a long time

Second Big Issue:

Nature – Nurture Issue: which has more effect on what we are like:

Heredity: Our biological structure that we inherit from our parents, based on our DNA or genes. Also called our genotype.

Environment: the experiences we have after conception that affect our physical, mental, and social characteristics.

Phenotype: Our characteristics, as determined by our heredity and our environment. How we look, sound, and act.

"Nature" approach: what we are like as an adult is determined by our biology, that we inherited from our parents.

"Nurture" approach: what we are like as an adult is determined by our experiences during childhood and later life.