Of the 2, respondents , between the ages of 18 and 75, 1, identified as male and identified as female. Almost half of the survey pool was from the United States 1, while the rest lived in nine different countries throughout Europe. The survey did not account for sexual identity or ethnicity of respondents. While the study's results were intriguing, you might want to take the findings with a grain of salt. Because the researchers didn't account for sexuality, the definition of "ideal" is in the eye of the beholder.