A researcher wishing to study the effects of attachment style in infancy on friendship formation in kindergarten MUST use a longitudinal research design.

Longitudinal Research Design

A methodological approach in research where participants are observed or tested repeatedly over a period of time to identify changes and developments.

Attachment Style

Refers to the pattern of bonding or relationship-building individuals have, which impacts how they relate to others. It is often categorized into secure, anxious, and avoidant styles.

Friendship Formation

The process by which friendly relationships are initiated and developed, often influenced by mutual interests, experiences, and social contexts.