Assessing Rushton and Bogaert (1987)

Rushton and Bogaert (1987) asserted:

“We averaged the ethnographic data on erect penis and found the means to approximate: Orientals, 4 to 5.5 in. in length and 1.25 in. in diameter; Caucasians, 5.5 to 6 in. in length and 1.5 in. in diameter; blacks, 6.25 to 8 in. in length and 2 in. in diameter.”

Let’s examine with new average self-reported data from Herbenick et al. (2014).


Given that Herbenick’s study is more recent and rigorous, Rushton and Bogaert’s average values inflate African penile dimensions (erect length and girth) by over 23% while deflating East Asian penile dimensions by over 14% (assuming Herbenick is accurate) [1].

Contra European stereotypes, Herbenick et al. found ‘Asian’ penile length comparable to European (diff. = 0.04cm) and ‘Hispanic’ (diff. = 0.01 cm) lengths. For this and other reasons, there seems to be a lack of race realist commentary on this study.

There has been the usual racist assertion [2] that Herbenick’s average U.S. penile length value of 5.6″ (14.15 cm) is due to East Asian oversampling. A similar claim was made for Wessells, Lue & McAninch (1996), another U.S. study. Given that ‘Asians’ are a U.S. minority and not a priority sample in peer-reviewed studies, claims as these are unsustainable.

The small African sample size (n = 38) may have been due to the study controls which minimized self-reported penile measurement inflation.

This race/history/evolution notes post looks into more of Rushton’s claims.

[1.] Granted Rushton is making a claim about ‘Orientals’ and the ‘Asian’ data from Herbenick may contain South Asians. Rushton does however, conveniently classify African Americans (Afro-Europeans) as ‘black’.

[2.] For example, a commenter claimed: ” …. I bet asians drag down the average overall. Take asians out of the equation and I bet the average is 7 inches.”


Herbenick, D., Reece, M., Schick, V., and S. Sanders. 2014. Erect Penile Length and Circumference Dimensions of 1,661 Sexually Active Men in the United States. The Journal of Sexual Medicine 11(1): 93–101.

Rushton, J., and A. Bogaert. 1987. Race differences in sexual behavior: Testing an evolutionary hypothesis. Journal of Research in Personality 21(4): 529-551.

Wessells, H. Lue T., and J. McAninch. 1996. Penile length in the flaccid and erect states: guidelines for penile augmentation. The Journal of Urology 156(3): 995-997.

Penis size: Taiwan

Penile length and appearance of young male – in Taiwan

Chuang, F-P., Wu, S-T., Lee, S-S., Yu, D-S., Chen, H-I., Chang, S-Y., and G-H. Sun.

Methods: The penile length (from pubo-penile skin junction to penile corona) in flaccid and erected states and the penile circumference were measured in random group of 300 young men aged 20-25 years and free from endocrine disorders and from congenital or acquired abnormalities of the penis.

Result: The median values of penile dimensions recorded in the present study are flaccid length 6.05 cm, flaccid circumference, at the middle of the shaft, 8.54 cm, and erected length 13.05 cm.

Source: Chuang, F-P., Wu, S-T., Lee, S-S., Yu, D-S., Chen, H-I., Chang, S-Y., and G-H. Sun. 2003. Penile length and appearance of young male – in Taiwan. Annual meeting & 25th General Scientific Meeting of the Taiwan Urological Association, p. 157.

Note: These are non-bone pressed and median values.

Penis size: Japan

Correlation Between Prostate Volume and Somatometric Parameters in the Patients Being Suspicious For Prostate Cancer

Motofumi, S., Nobuhiko, A., Tetsuya, F., Hiroshi, F., Yutaka, E., Hiroaki, N., Haruki, K., Yasuhiko, I., and H. Yukio.

We are interested in the relation between penile length (PL) and prostate volume (PV) because we have been impressed that PL is relatively long among the patients with benign prostatic hyperplasia…..

From April 2010 to September 2011, consecutive 431 male patients who underwent transrectal ultrasound-guided prostate needle biopsy were recruited for this study…. PL was measured by a ruler along the dorsum of the penis from the pubopenile junction to the tip of the glans as described by Wessells et al (J Urol 156:995-997, 1996)….

The mean age of patients was 67.9 +/- 7.0 (range: 47-84) years. Mean PL in flaccid and stretched states was 94.1 +/- 15.4 mm and 122.2 +/- 17.2 mm, respectively….

Source: Motofumi et al. 2012. Correlation Between Prostate Volume and Somatometric Parameters in the Patients Being Suspicious For Prostate Cancer. International Journal of Urology 19 (Suppl 1), 210-211. doi: 10.1111/j.1442-2042.2012.03167.x

Note: Age distribution of participants could cause depressed values, measured PL value is non-bone pressed stretched length (NBPSL) and study is much larger (n = 421) than Wessel (n = 80). It is however, similar to Wessel’s majority European sample study [90% European and African, 10% Asian, flaccid = 88.5 mm +/- 23.8, stretched = 124.5 +/- 27.1 mm, age: 54 +/- 14.37] as well as Chen et al. (2000) for European Jews in Israel:  flaccid = 83 mm +/- 13 mm, stretched = 125 +/- 14 mm (mean: 47 yrs, n = 55).  This study further invalidates the WorldPenisSize 109.2 mm value for Japan.