Skill level

Self-worth

Growth

Learning 

Minimal development.

Vocabulary rapidly develops in early childhood. 

None

To predict based on past and present characteristics.

To describe the changes typically occurring from about 35 to about 65 years of age.

To improve well-being 

To explain the causes of developmental changes

Fear

Isolation

Cooperation skills

Regression

Participants are forced to participate

Participants are deceived

Participants understand the study

Participants are anonymous only

Only cognitive processes

Interaction between individual and environment

Only biological factors

Only emotional development

Irregular patterns

Only at night

Absent

Constant

Object permanence

Egocentrism

Animism

Perspective-taking

Establish cause-and-effect relationships

Study only children

Observe behaviour only

Avoid variables

Attachment

Egocentrism

Reflexes

Moral development