Step 4, Question 2

Calculate the effect size, Cohen's d, for the study below.

Research Question

Do visible tattoos cause people to rate a person as being less attractive?

There has been some evidence in the past indicating that people with visible tattoos are viewed more negatively than people without visible tattoos (Resenhoeft, Villa, & Wiseman, 2008). Researchers attempting to mimic this study in 2010 conducted a similar study. They first obtained overall ratings of attractiveness for a woman with no tattoos shown in a color photograph. On a 7-point scale, the woman received an average rating of = 4.9, and the distribution of ratings was normal with a standard deviation of = 0.84. They then modified the photo and added a tattoo of a butterfly on the woman's left arm. They showed this new photo to a sample of n = 16 students at a local community college. They asked the students to rate the attractiveness of the woman on the same 7-point scale. The average score for the photo with the tattoo was M = 4.2.