The Origins of Music: Innateness, Uniqueness, and Evolution

Publication by Josh McDermott and Marc Hauser, here (.pdf file). Excerpt:

Music stands in sharp contrast to most other enjoyable human behaviors (eating, sleeping, talking, sex) in that it yields no obvious benefits to those who partake of it. The evolutionary origins of music have thus puzzled scientists and philosophers alike since the time of Darwin (1871). [...]

Every culture in the world has some form of music, and most cultures have apparently developed music independently from each other. At the very least, therefore, there seems to be some innate machinery motivating the production and appreciation of music. [...]

Infants pose an experimental challenge because unlike an adult subject, they cannot verbally report on their experiences. Instead, developmental psychologists make use of the fact that changes that are salient to an infant attract its attention, which can be measured via nonverbal behavioral responses. Although the behavioral assays vary, the fundamental logic underlying the method is the same: Exemplars from one category are repeatedly presented until the infant’s response -— sucking a non-nutritive pacifier for neonates, looking or orienting to a stimulus presentation for older infants -— habituates, at which point exemplars from either the same or a different category are presented. In a classic setup, a sample of music is played repeatedly from a speaker. Once the orienting response to the music habituates, the experimenter conducts test trials, some of which introduce some change to the music sample, such as a change in key or a rearrangement of the notes. If the infant is sensitive to the change that is made, then they will tend to look longer at the speaker following the trials containing the change. [...]

Lullabies—songs composed and performed for infants—are a particularly striking musical phenomenon found in cultures across the world and appear to represent a true music universal. Lullabies are recognizable as such regardless of the culture (Trehub, Unyk, & Trainor, 1993), even when verbal cues are obscured by low-pass filtering (Unyk, Trehub, Trainor, & Schellenberg, 1992). This suggests that there are at least some invariant musical features that characterize infant-directed music; this aspect of music directly parallels studies in language of infant-directed speech are often characterized as simple and repetitive by adult listeners, and may feature more descending intervals than other melodies (Unyk et al., 1992). Both adults and children perform lullabies in a distinctive manner when singing to infants; listeners can pick out the version of a melody that was actually sung in the presence of an infant. Infant-directed singing tends to have a higher pitch and slower tempo than regular singing and carries a particular timbre, jitter, and shimmer (Trehub, Hill, & Kamenetsky, 1997b).

The characteristics of lullabies, as well as the particular acoustic properties that adults and children imbue them with when sung to infants, appear to be tailored to what infants like. When infants are played both lullabies and adult songs under similar conditions, adults who watch them on videotape judge the infants to be happier when played the lullabies than when played adult songs (Trehub, 2000). The fact that the preferred characteristics of lullabies are culturally universal suggests that infant preferences for lullabies are indeed innate. Further, because no other animal parent vocalizes to its offspring in anything resembling motherese or a lullaby, this style of musical expression also appears to be uniquely human. At this point the origin of lullabies and their particular features remain unknown, but their existence suggests that at least one major genre of music is predominantly innate in origin and uniquely human.