No Child Left Behind

Running head: THE EFFECTS OF PRIMING AND EXPERIMENTAL BIAS ON SCORING RAT PLAY BEHAVIOR

The Effects of Priming and Experimental Bias on Scoring in a Rat Pup Play Behavior Experiment

Abstract

In this study researchers tested the effects of priming and experimental bias on students that were rating rat pup play behavior. Four classes were randomly assigned one of four different test sheets that had a combination either yes priming, no priming, yes experimental condition, and no experimental condition. The expected outcome for priming was that those participants that received it would rate the rat play behavior lower than participants that did not receive it. This hypothesis was supported. The expected outcome for the experimental condition was that those participants that were given experimental condition information of which rats were hungry would rate rat play behavior lower than those who did not receive this information. This hypothesis was not supported. It was also hypothesized that the exposure to both priming and experimental condition would result in more experimenter bias than either condition alone. This hypothesis was supported. These findings are important because of the social influences it confirms.

The Effects of Priming and Experimental Bias on

Scoring Rat Pup Play Behavior

It has been established over many studies that researcher’s may very easily find exactly what they are searching for (prove their own hypothesis) due to experimental bias (Rosenthal, Fode 1963). Experimental bias is the phenomenon where the outcome of an experiment is based towards a result expected by the human experimenter. For some reason humans are unable to remain objective on a topic when they have a basic opinion on the topic already. There are many factors that can have an effect on experimental bias. In this experiment priming and knowledge of the experimental conditions were used as the factors that could possibly affect the experimental bias. Priming is when a stimulus is utilized to sensitize the subject to a later presentation to the same type of stimulus. The knowledge of the experimental conditions was when the participant was either given information of the condition in the experiment or they weren’t.

The purpose of this study was to test to see if experimenter bias through knowledge of the experimenter conditions and priming effect the hand scoring measurements of play behavior in rats. This problem is important because it proves theories of how humans and animals react to different factors like priming, expectancy, and knowledge of experiment. With this information it will allow people to use these concepts to their advantage when raising their children, when persuading people, and in their everyday life.

The setup of this experiment consisted of four student groups that were asked to rate the play behavior of rats in a ten minute video clip. The first student group was just given the priming information in the experiment that hungry rats were less likely to engage in play behavior. The second student group was just given information of the experimenter bias information by being told which two rats were hungry. In group three the students were given both priming and experimenter bias information. The last group was the control group in this experiment, and they were given no information concerning the experimenter bias information or the priming information.

A previous study that was done to test the ratings researchers gave about rats when given different information about the laboratory rats is similar to this experiment in the way that priming was given to participants and experimental bias were used. In that study twelve experimenters each ran five rats through a simple discrimination, daily for a five day period. All the laboratory rats were regular rats that were divided into groups at random. Half of the experimenters were told that the rats they were observing were bred for maze brightness, and the other half of experimenters were told the rats they were observing were bred for maze dullness. The results of this study clearly indicated that the experimenters who believed that their rats were maze bright had rated their rats significantly higher than experimenter’s who were told they were observing maze dull rats (Rosenthal, Lawson 1963). The priming that was given to the participants in this study led them to have higher expectations for the rats that were bred for maze brightness, so whether the rats actually performed better in the maze or not, the participants may have rated them higher just based on the information they were given prior to the start of the experiment. Another reason why the rats could have been rated higher is the way the participants treated their rats. Rosenthal says that due to the experimenter’s subtle and unintentional communication of expectations that are portrayed to the subject may affect the performance. So the participants that were told their rats were maze bright may have treated their rats with more care and showed them more positive affection, than the participants that were told they were given maze dull rats that as a result may have treated the rats more carelessly with limited attention and care. This previous work correlates with this present day experiment in the way that priming was used on participants.

Another study that was done by Rosenthal and Jacobson (1966) testing if the expectancies that elementary school teacher’s have about their students would have an effect on how their student performs in the classroom. In this study teachers were told that some students were recognized as intellectual bloomers by a new test that they had taken. The students that were labeled as intellectual bloomers were actually chosen at random without the teacher’s knowledge. The results showed that students that were in the experimental group showed significantly higher gains in IQ than the students in the control group after an eight month period. These results were found to be stronger depending on the age of the children tested; the younger the children were the more effect the teacher’s expectancy had on the child’s IQ. Although the students were randomly assigned and never tested to be intellectual bloomers, the teacher’s expectancies affected the way the child felt about themselves in the classroom