AP PSYCHOLOGY

Detailed explanation-1: -A longitudinal study, like a cross-sectional one, is observational. So, once again, researchers do not interfere with their subjects. However, in a longitudinal study, researchers conduct several observations of the same subjects over a period of time, sometimes lasting many years.

Detailed explanation-2: -In a longitudinal study, researchers repeatedly examine the same individuals to detect any changes that might occur over a period of time. Longitudinal studies are a type of correlational research in which researchers observe and collect data on a number of variables without trying to influence those variables.

Detailed explanation-3: -4. Longitudinal research usually shows that intelligent in most abilities increase through out early and middle adulthood. Many adults show intellectual improvement over most of adulthood, with not decline, even by age 60.

Detailed explanation-4: -the rate and magnitude changes in intelligence seen in those entering old age showed greater decline in the 1st 3 cycles (till 1970); at the same time, younger members are scoring lower on tests at the same age. a decline in psychometric abilities is not reliably observed before 60, but is reliably observed by 74.