Humans are altricial beings. This means that we are born very immature, we are not fully developed. This happens to more animals, especially predators, who can afford the luxury of slow and prolonged development. The disadvantage is that we are helpless creatures in the early stages of life, dependent on the help of our fellow creatures, but the great advantage is that our nervous systems complete their development through a constant bombardment of social and cultural stimulation. If we were born ready, our brains would find it very difficult to learn language and social behaviour. Animals that play the game of life as prey, such as herbivorous mammals, are born much more developed, allowing them to run away within minutes of being born, but this speed seems to limit their cognitive plasticity to some extent.
Newborn babies are sensory sponges, and although it may take them months to say their first word and understand a simple sentence, we speak to them from the first second. It may seem like we are wasting our time by using grammatically complex sentences with these tender creatures, but this is not the case. Experiments show that pre-lingual babies easily pick up the emotional tone of what we say to them – a word of approval, a scolding, a little fright – and the reason for this ability lies in music: it turns out that people in every culture on the planet that has been studied spontaneously and without prior instruction speak to babies in song.
Both adults and pre-lingual babies have an innate ability to create and understand the emotional tone behind a sung message. In science, the musical way we speak to babies is called baby talk: it is oral language with exaggerated prosody, where we tend to use short sentences, where words are clearly separated and repeated, where high pitches (more high than low) and long vowels abound, resulting in a musically inflected speech that can convey emotional messages to babies. We use exactly the same kind of musical language with our pets, because it is the best way to communicate what we are thinking. For the archaeologist Steven Mithen, this priority in the development of music over articulated language is a relevant clue that seems to indicate, along with other evidence, that in the evolutionary process, before the dawn of symbolic language, humans used a system of oral and gestural communication in which rhythms, tempos and melodies allowed them to convey the emotional state of the sender and to manipulate the emotions and behaviour of the receiver.
If the universality and spontaneity with which we use this form of communication with babies is surprising, the naturalness with which we stop using it is no less surprising: at around the age of three, once a human child shows signs of understanding and mastering a grammatical language, the musical transmission of emotions takes a back seat, or rather is relegated to another level (however, we talk to other animals by singing all their lives because they never acquire a complex language). In adulthood, we maintain both systems of communication: thanks to the extraordinary tool of language, we can share with others, with extraordinary precision, everything that is on our minds and in our hearts. At the same time, the surprising variety of musical elaborations in today’s culture allows us to transmit and evoke all kinds of emotions.