An article by Sherman and Haidt  made some good points that I had not thought before. Like many others (apparently, as S&H consider this the typical view on the topic), I have learned that the appearance of cuteness, or kindenschema (by Lorenz in 1950s), is an adaptation to foster care for a helpless baby. S&H point out that, empirically:
- Newborns are not considered as cute as older babies – apparently the peak-cute is at 3 months and stays high until 10 to 36 months. If cuteness was supposed to elicit care, shouldn’t it be highest when the baby is most helpless?
An obvious objection would be that evolution does not create optimal adaptations, but adaptations that are better than the alternatives, in regard to cost-benefit. Perhaps reacting to short-lasting newborn features carries costs that are avoided by reacting to features that emerge later but also last longer? Still, I didn’t know this, and I wonder whether cuteness has a relevant relationship at all with the maternal instinct to care for the baby.
- Perceived cuteness is reduced when the baby shows negative expressions – i.e. when it would probably need the care most – while positive expressions enhance cuteness.
- Actual behaviors triggered by cuteness – baby-talk, petting, holding – are social behaviors, not caretaking behaviors. Caretaking is social behavior as well, but cuteness does not seem to trigger that any more than other social behaviors.
Thinking about cute puppies, it’s true that I’m more likely to pet them, hold them or play with them than take care of their physical needs per se.
The authors have an argument that cuteness is a mentalizing prime and related to expanding the moral circle, which I guess is ok, but did not create that TIL in me. However, the above points were news to me and made me realize (although the authors do not say it) that cuteness would be adaptation for other people than the primary caretaker(s). The tribe immediately comes to mind: by eliciting social interaction, the tribe creates a bond with the new member. And by eliciting social interaction with the baby (that has already developed some rudimentary ways to respond to social engagements), cuteness elicits first version of play – simple actions that are aimed at getting a positive reaction, which in turn elicits a positive reaction in the interactor. This is relevant for the idea of play that I’ve had , as I have primarily understood play (neurophysiologically: trying different things in a safe context in order to get positive reward) as a way to learn how the environment works. But, as is typical, in hindsight it seems obvious that play has the binding function as well – and this realization suggests the possibility that this binding function was first, and more complicated play may be an exaptation from that.
 Sherman, G. D., & Haidt, J. (2011). Cuteness and Disgust: The Humanizing and Dehumanizing Effects of Emotion. Emotion Review, 3(3), 245–251. https://doi.org/10.1177/1754073911402396
 Kivikangas, J. M. (2016). Affect channel model of evaluation and the game experience. In K. Karpouzis & G. Yannakakis (Eds.), Emotion in games: theory and praxis (pp. 21–37). Cham, Switzerland: Springer International Publishing. doi:10.1007/978-3-319-41316-7_2