Conditioned reinforcers are stimuli that can act like reinforcers even though they may appear to have little or no direct value

Which of the following is classified as a depressant?

a) cocaine b) alcohol c) heroin d) marijuana

A friend tells you that he conducted a scientific experiment

this summer in which he talked to ten plants and measured their growth. He found that these plants grew faster and taller than any plants he had ever grown. From your friend's research, can we conclude that talking to plants is the cause of their fast growth? a. Yes, because the scientific data was collected. b. Yes, because a positive correlation would found between talking and plant growth. c. No, because the placebo effect was not considered. d. No, because there was no control group.