Studies conducted to understand changes over time, in particular, populations or differences in respondents who share specific qualities are:

answer; i believe that the correct answer is ( troxel v. granville);

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; the automatic system because it is a "gut reactor"