Most published research focuses on describing differences, while neglecting
similarities that are arguably at least as interesting and important. In
Study 1, we modified and extended prior procedures for describing
similarities and demonstrate the importance of this exercise by examining
similarities between groups on 22 social variables (e.g., moral attitudes,
human values, trust) within six commonly used social categories: gender,
age, education, income, nation of residence, and religious denomination (*N
*= 86,272). On average, the amount of similarity between two groups (e.g.,
high vs. low educated or different countries) was greater than 90%. Even
large effect sizes revealed more similarities than differences between
groups. Studies 2-5 demonstrated the importance of presenting information
about similarity in research reports. Compared to the typical presentation
of differences (e.g., barplots with confidence intervals), similarity
information led to more accurate lay perceptions and to more positive
attitudes towards an outgroup. Barplots with a restricted y-axis led to a
gross underestimation of similarities (i.e., a gross overestimation of the
differences), and information about similarities was rated as more
comprehensible. Overall, the presentation of similarity information
achieves more balanced scientific communication and may help address the
file drawer problem.