skip to content

Darwin Correspondence Project

From J. F. McLennan   3 February 1874

3rd February 1874.

Your scheme of the development of marriage systems is (1) Polygyny and monogamy; (2) Polyandry; (3) Promiscuity; (4) Polygyny and monogamy in recurrence.

Jealousy, you conceive, determined the first stage; infanticide the second; polyandry, undermining natural jealousy or regulating it, brought on more or less promiscuity; and finally, a feeling of property in women growing up in aid of natural jealousy, reestablished polygyny and monogamy.1

You ask me whether I see any fatal objection to looking at polyandry as having preceded promiscuous intercourse, and, indirectly, what I understand by promiscuity and think of the statements often made as to its ancient prevalence.

Before submitting to you the few observations I have to make, I should like you to read my little book from p. 162 to p. 170, where there is a very imperfect thinking out of the initial stage.2 The inquiry is, remember, a human one; and man not only a creature with natural jealousy, but a combining, conspiring creature. The strongest gorilla may be free to conquer the weaker in detail, and thereafter be supreme in his group; gorillas not being developed up to the point at which the weaker can by combination for a sexual purpose subdue the stronger. Man alone exhibits this capacity for combination, and, I am sorry to say, our criminal records even in this country in late times show him capable of combinations for sexual purposes— several men joining to secure a woman and force her in turn. So far at the initial stage women were got by capture at the hands of more than one they would be apt to be common to their captors.

And now a word as to what I understand by promiscuity. You will see I have guarded myself somewhat against alleging its general prevalence. The import of my reasoning is that more or less of it and of indifference must appear in the hordes or their sections or some of them. I have nowhere defined it, but use it as a general term to denote the general conduct as to sexual matters of men without wives. Now, unless we assume that the nature of man has much changed, we may see in our own time and towns what this conduct has always been. The men in that situation, or very many of them, just do as they can, and are neither over-nice nor over-scrupulous as to the manner. As we go back in time I see no reason for thinking men were more nice or more scrupulous. On the contrary, they were less so; and I know no more instructive fact—disagreeable as it is, it is of high scientific interest—than that one practice (to denote it by the general term I have been using), paiderastia, in many countries became systematised. Thus in Greece the relation between a man and his youthful lover was constituted by a form of marriage after contract between the relatives on both sides. To allege, then, that there was a time when there was general promiscuity would be merely to say there was a time before marriage commenced—before any man had a wife. At that time there would be no uniform behaviour of all men; their indulgence would be as passion prompted and opportunity offered. We may see in the behaviour of other animals at that stage how various the behaviour may have been.

The object, I take it, is to ascertain what from that stage were the normal stages in the evolution of modes of marriage, or marriage systems. In the brute stage we may see analogies to marriage systems, e.g. the gorilla may be said to keep a harem and to be polygynous, but it would be a misuse of terms to speak of him as married to his females, or of his females as his wives. Marriage began with the first consortships of men and women, protected by group opinion.

Now I agree with you that from what we know of human nature we may be sure each man would aim at having one or more women to himself, and cases would occur wherein for a longer or shorter time the aim would be realised, and there would be instances of what we may call polygyny and monogamy—your first stage; but, observe, every case of polygyny would cause a case or cases of men without women. That is, supposing you correct in thinking that a policy of female infanticide was later than marriage3—I incline to the opposite opinion, but it is a point that cannot be well settled—there would yet be a disturbance of the balance of the sexes caused by a practice of polygyny; so that the reasons which move you to conceive there must have been polygyny at the first, are also reasons for conceiving that there was alongside of it polyandry (or its equivalents). Nay, the presumption is that the latter would be on a larger scale than the former, and it certainly would be so, so far as the men were concerned; and their training probably was more important than that of the women, so far as the future of marriage was concerned.

The first stage, then, if marked by polygyny and monogamy, must have also been marked by polyandry or its equivalents.

I take it, polygyny, monogamy, and polyandry (or its equivalents), must have occurred in every district from the first, and grown up together into systems sanctioned by usage first and then law. But I would put them in this order—

Polyandry .... the more common.
Monogamy .... less common.
Polygyny .... still less common.

I think I can show monogamous systems to be, on the whole, post-polyandrous systems; that the normal development was through the forms of polyandry—and through the break-down of polyandry.

As to polygyny, it is to be observed that it is necessarily everywhere the privilege of the few, not the practice of the commonalty. As time passed monogamy would tend in advancing communities—in which the tendency inevitably is towards an equal distribution of the means of well-being among the members of society—to become the common practice; and sentiments springing from it—as the common lot—would be unfavourable to, and in time lead to the condemnation and prohibition of polygyny. The countries in which polygyny is said to prevail are really only countries in which it is still permitted. As a system it can have had less to do than any other with the history of marriage on the whole.

Your most important suggestion, viz. that the policy of infanticide may have been of late adoption, I shall carefully consider. At present I see no grounds for it; but I am forced by your throwing it out to think of fresh inquiries in one or two fields that have always been a puzzle to me, e.g. the native Australians.

Since I wrote my book I have accumulated much information about the so-called promiscuity of savages. Perhaps some day we may talk of it.

My remarks are put hurriedly before you at what they are worth, and I must send them in all the deformities of a first expression.

P.S.— In re-reading I notice I have not made myself quite distinct, though you will probably catch enough of my meaning. Polyandry, in my view, is an advance from, and contraction of, promiscuity. It gives men wives. Till men have wives they may have tastes, but they have no obligations in matters of sex. You may be sure polygyny in the early stage never had the sanction of group opinion. They would all envy and grieve at the good of their polygynous neighbour. Polygyny, then, did not at first give men wives. Wifedom begins with polyandry, which is a contract. If I had time I would re-write this, and try and make it more worth your while reading. I should say I have not been on this branch of my subject for some time. I have been trying to feel my way back to the state of the primitive groups by a variety of avenues apart from marriage; notably through the totem and its extensive connections.


CD may have elaborated the brief discussion of primitive marriage in Descent 2: 358–63 in a letter to McLennan that has not been found. CD revised this discussion in Descent 2d ed., pp. 587–91, but made no mention of polyandry as part of the sequence. CD had mentioned polyandry as a consequence of female infanticide, and McLennan’s belief in former almost universal polyandry, in Descent 2: 365.
There is an annotated copy of McLennan’s Primitive marriage (McLennan 1865) in the Darwin Library–CUL (see Marginalia 1: 559–61). In pages 162–70, McLennan suggested that female infanticide arose out of scarcity of resources and the assumed inability of women to support themselves by hunting; that polyandry arose as a consequence of the shortage of women; and that promiscuity developed as a solution to quarrels over women.
CD’s suggestion that female infanticide came later than marriage may have been in a missing letter to McLennan.


Descent 2d ed.: The descent of man, and selection in relation to sex. By Charles Darwin. 2d edition. London: John Murray. 1874.

Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.

McLennan, John Ferguson. 1865. Primitive marriage: an inquiry into the origin of the form of capture in marriage ceremonies. Edinburgh: Adam and Charles Black.

Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.


Discusses the evolution of marriage systems; considers the scheme of development CD proposes: 1. Polygyny and monogamy; 2. Polyandry; 3. Promiscuity; 4. Polygyny and monogamy in recurrence. Explains what he understands by promiscuity. JFM believes that polygyny, monogamy, and polyandry must have occurred in "every district from the first, and grown up together into systems sanctioned by usage first and then law". Considers polygyny necessarily the privilege of the few and, as a system, believes it had less to do than any other with the history of marriage. He sees polyandry as an advance from promiscuity and the stage at which contractual obligations between men and their wives begin.

Letter details

Letter no.
John Ferguson McLennan
Charles Robert Darwin
Sent from
Source of text
McLennan 1896, pp. 50–5

Please cite as

Darwin Correspondence Project, “Letter no. 9264,” accessed on 7 July 2020,

Also published in The Correspondence of Charles Darwin, vol. 22