Professor Grant is interested in studying the development of a sense of humor. She collects data from groups of 6-year-olds, 16-year-olds, 26-year-olds, and 46-year-olds. What type of research design is Professor Grant using?

Cross-sectional design

Explanation:

Cross-sectional design research could be seen as a research where information for research are been collected from various population at a particular period of time. They are used in different cases, to find ratio in an ailment spreading and what's leading to the increase. Professor Grant collection of data from various groups to study developmental sense of humor indicates a cross sectional design.