Jim and Bob both have negative attitudes toward review sessions. Jim's instructor explains that review sessions can help to focus study efforts. Jim thinks carefully about this explanation and then changes his attitude using the route to attitude change. Bob's instructor also tells him that review sessions are useful. Bob doesn't think much about the explanation, but he is impressed by his instructor's confidence and thinks that she is very intelligent so he changes his attitude using the route to attitude change.

Central , Peripheral

Explanation:

Central route of persuasion tends to change attitude depends on message content as the person is convinced through idea, thought and meaning meaning behind the message .

Peripheral route of persuasion is dependent upon other factors apart from content of the message. They find other cues more persuasive for deciding about listener's message.

According to the question,Jim has central route to attitude change because he focused on content of instructor and got persuaded but Bob got persuaded through confidence and intelligence of instructor ,so he has peripheral route to attitude change.

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.        

because he had a big bear belly