What type of research design involves studying several age groups at the same time?

The cross-sectional design is characterized by studying different age groups simultaneously to gather data on various characteristics or behaviors at a single point in time. This approach allows researchers to compare the differences and similarities among groups of varying ages, providing insights into how certain factors, such as development or social behaviors, may differ across life stages.

This design is particularly useful in developmental psychology, as it enables the examination of age-related differences without the time commitment required by longitudinal studies, which follow the same group of participants over an extended period. By using a cross-sectional design, researchers can efficiently assess and analyze trends and patterns related to aging and development across diverse populations.