Geoffrey Miller

Abstract

Human music shows all the classic features of a complex biological adaptation.

Adaptations must be explained either through natural selection for (individual)

survival benefits or sexual selection for courtship and reproductive benefits.

Darwin argued that both birdsong and human music evolved as sexually selected

courtship displays. Whereas his explanation of birdsong is widely accepted, his

courtship hypothesis for human music has been neglected. Darwin’s courtship

hypothesis can be updated in the light of contemporary evolutionary psychol-

ogy, biological signaling theory, and sexual selection theory. Some features of

music seem to function as costly and reliable indicators of the producer’s fitness,

and others may have evolved through Fisher’s runaway process as purely aes-

thetic signals. Although human music is usually made in groups, like many other

courtship displays, no group selection account is necessary. To distinguish better

between survival and courtship functions of music, we do, however, need much

more cross-cultural, quantitative data on music production as a function of age,

sex, mating status, and audience composition. Given that almost all complex

acoustic signals produced by other species are courtship displays, this hypothe-

sis for human music is not only better supported by music’s design features, but

should be considered the evolutionary null hypothesis.

A Darwinian Approach to Music Evolution

... it appears probable that the progenitors of man, either the males or females
or both sexes, before acquiring the power of expressing their mutual love in artic-
ulate language, endeavored to charm each other with musical notes and rhythm.
(Darwin 1871:880)

In The Descent of Man, and Selection in Relation to Sex, Darwin (1871)

devoted ten pages to birdsong and six to human music, viewing both as

outcomes of an evolutionary process called sexual selection. Darwin’s

idea that most birdsong functions as a courtship display to attract sexual

mates is fully supported by biological research (e.g., Catchpole and Slater

1995), but his idea that human music evolved to serve the same function

has been strangely neglected. Although much has been written about the

origins of human music (e.g., Rousseau 1761; Blacking 1987; Dissanayake

1988, 1992; Knight 1991; Storr 1992; Tiger 1992), very few theorists have

taken a serious adaptationist approach to the question. Those who have,

usually searched in vain for music’s survival benefits for the individual

or the group, overlooking Darwin’s compelling theory that music’s ben-

efits were primarily reproductive and best explained by the same sexual

selection processes that shaped birdsong. This chapter has the simple

goal of reviving Darwin’s original suggestions that human music must be

studied as a biological adaptation, and that music was shaped by sexual

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Evolution of Human Music through Sexual Selection