RWA scores show negligible genetic influence because identical and fraternal twins correlate similarly.

Evidence

Lykken’s first study was completed by May 1990 (Lykken, personal communication, May 14, 1990). He sent the RWA Scale to about half of the twins in the Minnesota Twin Registry and obtained scores from 177 pairs of monozygotic twins, and 145 pairs of dizygotic twins, all raised together. (You know what I mean.) The results were broken down by gender. The correlation between RWA scores of male identical twins was .67, while that for females was .73. The values for male and female dizygotic twins were . and .71, respectively (Lykken, personal communication, March 14, 1994). These data basically looked like the Traditionalism Scale results to me. There was not much difference between identical and fraternal twins, and therefore hardly any evidence for genetic determinants of authoritarianism. — Bob Altemeyer, The Authoritarian Specter, 952

Categorization

• XREF: Directly contradicts the earlier genetic claims from the broader Minnesota twin studies — same registry, opposite conclusion depending on the measure.