Do Gender and Age Affect Smiling? (continued)

Paper and pencil to record

Excel, the computer program for spreadsheets (optional)

Procedure

In order to do this investigation I had to decide how I was to rate a smile. I decided that a smile was when the corners of the mouth were turned up, but not in a forced way like in a grimace or sneer. Then I needed to see how consistently I could rate a smile. To check the accuracy I took a page of a yearbook, found the number of students on the page, and how many girls were smiling and how many boys were smiling. This was then repeated five times. The data was collected and put into a table and then the Standard Deviation and mean was calculated using Excel. 

The margin of error was calculated. This was the difference between the mean minus the STDEV to the mean plus the STDEV. 

Having found the margin of error, which showed how accurate I could rate the photographs, the yearbooks were gathered. These were grouped from 1st grade through seventh grade, excluding fourth following the same group of students. There was a second group that had random student groups from fifth through eighth. In all these yearbooks the photographs were rated for smiling or not smiling and the data was collected to show the number of boys smiling and girls smiling in each grade. Tables were put together. There were two tables, one representing the mix of students from grades fifth through eighth and one to represent the same kids, first through seventh. These tables are as follows: 

Discussion

In the beginning of this study I had to find out how accurate I could rate the photographs, my margin of error. It was found to be 9 %. For the results to be significance there had to be a 9 % difference between scores. Anything less than that could not be marked as a real difference. 

In the yearbooks where different students were studied I found there was a significant difference between the genders in fifth, seventh, and eighth grade with girls smiling more. Fifth and seventh grade differences were similar but in eighth grade there was a difference of 27 %, girls smiled 81% and boys only 54 %. There was no significant difference in sixth.

With the same students that were studied there was no significant difference until sixth and seventh grade where the girls smiled more than the boys. Seventh grade had the biggest difference with the girls smiling 28% more than the boys did. 

These results were similar to the study we replicated and they support the hypothesis.

Conclusion

This study was to find out if there was a difference between boys and girls smiling and does it change over time? The hypothesis of the study was that as you get higher in the grades girls will smile more than the boys. I 
found that by seventh and eighth grade girls are smiling more. This was what I was hoping to find.