Biological Markers of Sex: Two Studies Comparing Direct and Indirect Methods of 2D:4D Ratio Measurement

• In Event: ICA Interactive Paper/Poster Session III
  In Interactive Poster Session: Communication Science and Biology Interactive Poster Session

Abstract

2D:4D finger ratio (the ratio between the second and fourth digit) has been implicated as a
sexually-dimorphic and stable proxy for androgen levels (i.e. testosterone) during prenatal sex development (Manning, Scutt, Wilson & Lewis-Jones, 1998). Studies have linked 2D:4D to a wide array of topics relevant to social scientists including sexual orientation/sex role identity, health factors, cognitive ability, psychoticism, neuroticism, sensation seeking, and dominance (Putz, Gaulin, Sporter & McBurney, 2004). While some trends are established, however, inconsistencies remain, including patterns, significance of left vs. right hands, strength of effect sizes, and reliability of various methods of measurement. In this paper, two methodological studies are presented; one compares indirect and direct measures, and the other compares two different hand orientations during direct measurement. Pearson r and intraclass correlation coefficients (ICCs) reveal high reliability of measurements in both studies. Implications of these findings in light of empirical and meta-analytical findings are discussed.

Authors

• Chelsea Lonergan, U of California, Santa Barbara

• Rene Weber, U of California - Santa Barbara