Identify the correct statements about gender differences in the population, assuming there is no interference from reproductive technology, social programs, or violent conflicts.

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.        

answer; i believe the answer is 80%, plz check first good luck;

i honestly have no idea

answer; make laws;