The music preferences data were collected as part of an ongoing study of music preferences involving volunteers assessed over the World Wide Web (http://www.outofservice.com/music-personality-test/). The web site is a non-commercial, advertisement-free web site containing a variety of psychology measures. Potential respondents could find out about the site through several channels, including search engines, or unsolicited links on other web sites. The data reported in the present research were collected between 2001 and 2013.
Respondents volunteered to participate in the study by “clicking” on the music-preference test icon and were then presented with a series of questions about their music preferences, personalities, demographic characteristics, and place of residence. After responding to each item and submitting their responses, participants were presented with feedback about the music preferences based on their responses to the items.
As in all studies that collect data from individuals over the Internet, there is the possibility that respondents may complete a survey multiple times. Repeat responding has the potential to produce unreliable and misleading results so it was necessary to remove data from potential repeat responders.
Several criteria were used to eliminate repeat responders. First, one question included in the survey asked: “Have you ever previously filled out this particular questionnaire on this site?” If respondents reported completing the questionnaire before, their data were excluded. Second, IP addresses were used to identify repeat responders. If an IP address appeared two or more times within a 1-h period, all responses were deleted. Third, if an IP address appeared more than once in a time span of more than 1 h, consecutive responses from the same IP address were matched on several demographic characteristics (gender, age, ethnicity) and eliminated if there was a match. Finally, only respondents who indicated that they lived in a metropolitan region with more than 500,000 inhabitants were included.Footnote 1
Implementation of these criteria resulted in complete data for 119,316 individuals, out of which 91,948 respondents live in metropolitan regions with more than 500,000 individuals. The median age of respondents is 24 years (SD = 11.04 years). Of those who indicated, 59% are female, 75% are white, 6% are African American; 7% are Asian; and 7% are Latino.Footnote 2 Of those who provided information about their social class, 21% said that are working class; 20% lower-middle class, 39% middle class, 17% upper-middle class, and 2% were upper class.
To ensure that each metropolitan region was fairly represented, we correlated the percentage of total respondents from each metropolitan region in our sample with the percentage of the total US population for each metro using data from the US Census Bureau for the year 2010. The percentage of respondents from each metro in our sample was directly proportional to the 2010 US Census Bureau’s estimates of the population of each metro, r = .96.Footnote 3
Past research on Internet-based surveys suggests that minority groups are vastly underrepresented on the Internet (Lebo 2000; Lenhart 2000). Therefore, to determine whether our sample overrepresented individuals from particular racial groups or social classes, we correlated the percentage of respondents for each group from the Internet sample with the percentage of the population of that group within each metro. For example, we correlated the percentage of Asian respondents from each metro with the US Census Bureau’s estimate of the percentage of Asians in each metro. The correlations for African Americans, Asians, Latinos, Whites, and “Other” ethnicities, respectively, were .92, .94, .95, .74, and .67, all ps < .001.
Overall, these analyses indicated that our Internet-based sample was generally representative of the population at large. Indeed, with the exception of “Other” ethnicities, the racial composition of our sample matched almost perfectly the US Census Bureau’s population estimates. It appears as though our sample underrepresented individuals from lower and upper classes, but the sample is still far more representative of the US population than are most psychological studies that rely on convenience samples (Gosling et al. 2004).
Identifying music preferences
Music preferences were measured using the revised version of Rentfrow and Gosling’s (2003) Short Test of Music Preferences (STOMP-R). The STOMP-R is a 21-item survey designed to measure individual differences in musical preferences. Using a rating scale with endpoints at 1 (Dislike) and 7 (Like), respondents indicate the degree to which they like each of the following music genres: alternative, bluegrass, blues, classical, country, electronica, folk, gospel, heavy metal, rap, jazz, new age, opera, pop, punk, reggae, religious, rock, soul/R & B, funk, and world (Rentfrow and Gosling 2003).