Cuteness could be an evolving linguistic concept because its defining characteristics were perhaps considered obvious or even ineffable for much of history. It was not until the 20th century that the Nobel laureates Konrad Lorenz and Niko Tinbergen described the ‘infant schema’ that humans find cute or endearing: round eyes, chubby cheeks, high eyebrows, a small chin and a high head-to-body-size ratio. These features serve an important evolutionary purpose by helping the brain recognize helpless infants who need our attention and affection for their survival.
In fact, cute judgments might be fundamental to human perception. Examining magnetic brain activity in subjects presented with infant and adult faces, Kringelbach and his colleagues at Oxford have found that the brain starts recognizing faces as cute or infantile in less than a seventh of a second after the face is presented to subjects. His group has concluded that cuteness is a key that unlocks the brain’s fast attentional resources before also influencing slower brain networks responsible for compassion and empathy.
If cuteness is such an important key, might a locksmith counterfeit a master key? Decades ago, Lorenz and Tinbergen also introduced the concept of a supernormal stimulus: a stimulus far more salient or intense than any occurring in nature. In a classic experiment, Tinbergen discovered that geese preferred to roll volleyballs towards their nests over real goose eggs. In fact, volleyballs are supernormal stimuli because their big, round, white shape is more egg-like than real goose eggs.
Similarly, Pikachu’s baby-like features might exceed those of real infants, making the character a supernormal stimulus: unbearably adorable, but without the high maintenance of a real baby. Needless to say, our ‘sense of cute’ did not evolve to nurture faux animals such as Pikachu, but our brains have been hijacked nonetheless by the unnaturally big eyes and childlike features of such cute characters. Similarly, our ability to sense sugar in food did not evolve for us to enjoy chocolate milkshakes, but to steer us towards naturally occurring sources of sugar in fruit and other foods.
Cute cartoon characters, junk food, videogames, and other supernatural stimuli might engage the nucleus accumbens, a critical piece of neural machinery in the brain’s reward circuit. The nucleus accumbens contains neurons that release dopamine, a brain chemical that, among other things, encodes such stimuli. Much like drugs of abuse, supernormal stimuli are hypothesized to activate the nucleus accumbens, directing the brain’s full attention towards the reward in question. An international team of researchers studied the phenomenon by artificially manipulating the infant schema of baby faces in photographs to create what might be considered supernormal stimuli—faces more or less baby-faced, or cute, than a normal infant might appear. Women were presented with the real and manipulated images while their brains were scanned using functional magnetic resonance imaging (fMRI). As the researchers hypothesized, the heightening or diminishment of cuteness had a significant effect on metabolic activity in the nucleus accumbens, suggesting that this brain region both responds to supernormal stimuli and plays a crucial role in triggering altruistic, nurturing behavior towards babies.