By Rosa Parker
Music soundtracks every aspect of our life; be it lullabies, a club classic, the first dance at a wedding, or the final curtain at a funeral. It has the power to lift or destroy moods, and to convey emotion without words. Music is also puzzling in its ubiquity: it is present in every studied human culture. Music-making was either evolutionarily advantageous, or a random by-product of evolution. So, what advantages did it offer our predecessors? And if it offered none at all, how exactly did it evolve?
Darwin was the first known person to ponder the evolutionary origins of music. In his book, The Descent of Man, he attributes its emergence to sexual selection.
Sexual selection is a form of natural selection. Evolution is driven by sexual preferences for certain characteristics in the opposite sex: in this case, the desirable characteristic of music-making. Darwin thought that the expression of complex emotions like love through music-making, would be advantageous in attracting a mate. The idea of music influencing mate selection gives an answer as to how music-making is so common in humans and primates, yet only resolves the question on a mechanistic level. It fails to encompass the phenomenon of social bonding.
A paper published in 2016 by Weinstein et al. records that choir singers had a higher pain threshold after performing as a group than non-choir singers. Collectively creating sound and harmonies releases dopamine, a chemical responsible for feelings of pleasure and reward. This can lead to participants experiencing positive feelings of mutual accomplishment, and pain relief. The effect of music in enhancing group social bonding is exemplified in many aspects of human culture, from hymns to football chants, and campfire songs to national anthems. These mutual feelings encourage cooperation between individuals by increasing a feeling of connectedness to others and interpersonal liking. Strengthening social bonds is crucial for facilitating group cohesion: there are costs to living with others, such as increased competition for mates. Living in a large group can also provide survival advantages, however, such as a decreased risk of predation. It is essential to keep up morale and cooperation to maintain stability within the group, and it is possible that this tool for bonding paved the way for the evolution of our own Homo sapiens.
Take another hypothesis, parent–infant bonding. The pitch of lullabies is very similar across different cultures: we talk to children in a specific way, perhaps due to the parenting success this may facilitate. Silence is often perceived as a sound of danger in nature, so a parent soothing their offspring with song can alleviate stress and help bonding. None of these ideas are mutually exclusive, and are tied together in a 2020 paper by Savage et al., which proposes that music and genes coevolved for social bonding: the ability to make music that could promote social bonding was genetically and culturally selected for, and music has subsequently evolved to become more complex over time.
A preprint published by David Schruth in December 2020 took a more subtle route to explain the emergence of music. Schruth and his colleagues analysed sounds produced by primates, discovering almost every primate family made ‘music-like’ calls. They defined music as the ability to make a call with 2 different repeated notes, aiming to reduce bias when studying this phenomenon: it is easy to disregard the repetition of two notes in comparison to the complex melodies we can produce today. Schruth’s approach, however, led to the conclusion that the common ancestor of all primates must have been able to produce a call with ‘music-like qualities’. He hypothesised that singing demonstrated control over vocal cord muscles, indicating to other primates that the singer was acrobatically adept, and therefore physically fit. This distinction could have driven sexual selection, as a skilled mate could provide food for their offspring or defend their territory.
Finally, none of these views necessarily conflict. Whilst music may have initially been selected for as an indicator of agility, its propagation and ubiquity could be a result of the strong social bonds it helps forge. It is remarkable that a trait capable of causing profound emotional responses may have emerged for a different reason, and that music could have coevolved with humans to shape and stabilise our society as we know it today. Looking far into the future, could music-making facilitate new means of communication, or lead to the formation of a more harmonious society? We are still evolving, and music is no different.