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Darwin Correspondence Project

From John Beddoe   21 August 1869


Aug 21. 1869

Dear Sir

I enclose the results of several more years of observation on the point of conjugal selection, respecting which you wrote to me—1 I am sorry that I have been so long in sending these particulars, but must beg you to excuse my tardiness, as I have been intensely occupied in various ways, & have had no one by me to whom I could entrust the business— You will see that the tendency of these later figures is to confirm the former ones—2

In this later investigation I have excluded the women between 20 & 25, & between 45 & 50, who were included in the former one—3 I do not think the hair grows notably darker after 25 in most people—4 But red hair does become less vividly red—

To test the matter further, I will divide the women into two classes, viz, those above & those below 35, & let you know the result—5

Your apology for troubling me in this matter really made me feel ashamed— I think there can be but few of us humbler cultivators of natural science, who would not feel it an honour to be permitted to contribute his stone towards the building of your great edifice— At any rate, it will always be a pleasure to me to do for you anything that you may esteem a service— I hope before long to send you a copy of a statistical memoir of mine “on the stature & bulk of Man in Britain”, which is being printed in the Anthropological Memoirs—6

I am, dear Sir | Yours faithfully | John Beddoe M.D.


Women of the lower class, from 25 to 45 years of age—natives of Bristol and the neighbourhood for the most part—

Red Fair Brown Dark Black Total

Single 11.5 17.5 51.5 44 5.5 130


per cent 8.8 13.4 39.6 33.8 4.2


Women 23 8312 21812 31012 4212 678

3.4 12.3 32.2 45.8 6.2

CD annotations

1.1 I enclose … business— 1.5] crossed pencil
1.3 but must … tardiness,] scored red crayon
2.2 I do … red— 2.3] scored red crayon
3.1 I will … result— 3.2] double scored pencil
4.1 Your … Memoirs— 4.7] crossed pencil

End of table:

‘ 23 8312 21812 31012 4212 6780’ ink


CD’s letter has not been found. He had evidently written with questions concerning Beddoe’s paper ‘On the supposed increasing prevalence of dark hair in England’, in which Beddoe suggested sexual selection as a mechanism for a perceived change in the predominant hair colour in the human population (Beddoe 1863).
From his analysis of data on the hair colour and marital status of 737 female patients at Bristol Royal Infirmary aged between 20 and 50, Beddoe had concluded that fewer light-haired women than dark-haired women married, and suggested that this would eventually result in greater prevalence of dark hair in the general population (Beddoe 1863, p. 312).
See n. 2, above.
Beddoe had qualified his published conclusions with the caveat that hair darkens with age (Beddoe 1863, p. 312 n.).
Beddoe 1869.
There is an analysis of the combined data from Beddoe 1863 and this table in CD’s handwriting in the Darwin Archive–CUL (DAR 85: A24); there are also calculations of percentages based on Beddoe’s tables made by George Howard Darwin, some with CD annotations (DAR 85: 15, 16, 19, 20, 25–28). Although CD cited Beddoe’s work on human stature in Descent, he did not use any of the data on hair colour; see also CD annotations to letter from John Beddoe, 13 September 1869.


Encloses results of several more years of observation on conjugal selection and hair coloration.

Letter details

Letter no.
John Beddoe
Charles Robert Darwin
Sent from
Source of text
DAR 85: A21–3
Physical description
4pp †, table †

Please cite as

Darwin Correspondence Project, “Letter no. 6865,” accessed on 19 April 2019,

Also published in The Correspondence of Charles Darwin, vol. 17