Dr. Blau collects data about the perinatal circumstances of all of the infants born in Buffalo, New York, from January through April 1978. He contacts these individuals when they are 10, 18, and 35 years of age and conducts assessments of their personality, psychosocial functioning, and mental health status. This is a design:

Longitudinal study design

Explanation:

A longitudinal study design is a type of research design that has to do with observation of same variables repeatedly over a period of time. A longitudinal study can be over a shirt period of time or a long period.

This researcher is interested in collecting data on perinatal circumstances and he is collecting data from these persons at different times of their life. When they are 10, 18 and when they are 35.

okay? wahts the question

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.