When 4-year-old Mariella thinks of activities, behaviors, or personal characteristics as being "for mommy" or "for daddy," she is using which of the following?

_______________________proposed dynamic systems theory based on her study of the

development of walking. a. Tanner b. Dennis c. Thelen d. Kerr

Which of the following is a basic requirement of single-group cohort designs?

a) A sample that maintains its status on the characteristic of interest over time b) Assessments of different people about the same subject c) Assessments occurring at two or more points in time d) A sample that may serve as its own control