On Cuteness: Unlocking the Parental Brain and Beyond

Abstract

Cuteness in offspring is a potent protective mechanism that ensures survival for otherwise completely dependent infants. Previous research has linked cuteness to early ethological ideas of a 'Kindchenschema' (infant schema) where infant facial features serve as 'innate releasing mechanisms' for instinctual caregiving behaviours. We propose extending the concept of cuteness beyond visual features to include positive infant sounds and smells. Evidence from behavioural and neuroimaging studies links this extended concept of cuteness to simple 'instinctual' behaviours and to caregiving, protection, and complex emotions. We review how cuteness supports key parental capacities by igniting fast privileged neural activity followed by slower processing in large brain networks also involved in play, empathy, and perhaps even higher-order moral emotions.

Keywords: Kawaii; affiliative; caregiving; emotion; neuroimaging; pleasure.

Figure 1. Behavioural measures of cuteness of faces across species

A) The proportions of features of a face can be used to provide objective measurements of cuteness in infant and adults [20]. B) Adult men and women (who are not yet parents) differ in their liking ratings but not in the amount of effort they expend on viewing natural images of infants with varying levels of objective cuteness [22]. C) Artificially changing the proportions of the faces of humans, dogs and cats can change their perceived cuteness, although questions have been raised over the ecological validity of such nonecological image manipulations. D) Five year old children find the young significantly cuter than the adult of different species [24].

Figure 2. Cuteness elicits fast responses in the human brain

A) Infant faces are examples of cute stimuli which have been shown to elicit fast brain responses in the orbitofrontal cortex (OFC, ~130ms) at the same time as responses in the fusiform face region [15]. B) Artificially manipulating the cuteness of infant faces have been shown to correlate with changes in the BOLD signal in the nucleus accumbens, part of the pleasure system [41]. C) Very fast neural responses (~50ms) are found in the human brainstem to both positive and negative infant vocalisations (babbling, laughter and crying) [37]. D) Similar to the fast brain response to cute visual stimuli, infant crying elicits activity in the OFC (~140ms) at the same time as activity in primary sensory cortices [58].

Figure 3. Even minor facial abnormalities can change cuteness perception

A-D) Behavioural findings to images of human and animal with cleft lips show significantly stronger liking and wanting of non-cleft stimuli [84]. E) Neuroimaging findings of significantly diminished fast processing (<140ms) in OFC of cleft infant faces compared to cute infant faces in nonparents [39].

Figure 4. Putative brain mechanisms of cuteness and other infant survival-relevant stimuli elicit fast and slow affiliative behaviours

A) The core affect elicited by cuteness is generated by the pleasure network in the human brain (shown here in one hemisphere only) with the nucleus accumbens and ventral pallidum (in red) and other main pleasure coding regions (in green). Clockwise views (from bottom left) are from top, front, side and 3D perspective. The connections indicate the tentative functional networks mediating hedonic “liking” reactions and subjective pleasure ratings [64]. B) The optimization of resource allocation for survival depends on the engagement with rewards that act as motivational magnets to initiate, sustain and switch state. Typically, the pleasure cycle consists of appetitive, consummation and satiety phases, where wanting, liking and learning mechanisms drive the phase transitions of the metastable brain states [102]. C) Subliminally presented stimuli and non-survival related stimuli often fail to provide ignition of activity that is made available for global access [103]. D) Cuteness and other infant survival-relevant stimuli provide privileged routes to fast ignition of activity leading to glocal access providing the necessary slowness for prosocial caregiving and play behaviours [43, 93, 104]. Abbreviations: Nucleus accumbens (NAc), ventral pallidum (VP), parabrachial nucleus (PBN); medial OFC (mOFC); lateral OFC (lOFC); mid-anterior OFC (midOFC); dorsal anterior cingulate cortex (dACC); rostral anterior cingulate cortex (rACC); and periaqueductal gray (PAG).