I believe the answer is: <span>a purely experimental branch of natural science
According to watson, every act of treatments that is aimed to fix a certain psychological problems is only based on prediction since there is no sure thing to predict other people's behavior due to the number of factors that might influence it. Because of this, he refers to psychology as a 'purely experimental;' branch.</span>
However, United States imports from the trade agreement countries were Jess in 1938 than 1937 in every case except Haiti and Honduras, and United States exports also dropped except to Honduras, Colombia and Costa Rica.