In fact non social species, like felines, are unmoved or even aggressive toward babies not kin related to them.
But we are primates, and being primates very social, we are subject to trivers reciprocal altruism, in other words: childs are very prone to help strangers if they feeds them. They can be adopted and parassitated as muscular force in exchange of a small piece of the meal, smaller than those of the natural childs of course, as foster care studies have demonstrated. So we can find others child very attractive too, because they can be very useful to ...
Here is the final, most likely explanation for the cuteness paradox:
1 - Cuteness genes are positively selected by many things, but the main filter, at least in mammals, is THE MOTHER INVESTMENT. Puppies (humans, bunnies, all of them..) compete for the investment of the mother, because she is the one that feeds them. They cannot feed themselves until they are adults. Cuteness is a deceivement device and (because it costs physical resources) an honest signal for communicating the mother that the deceiver is the puppy most worth of the maternal investment. Ev...
I find the bunny cuter than any human baby I ever seen, and I believe that the majority of people will share the same feeling, but our opinions are aneddotical and do not constitute scientific proof. What we need is to take a statistically unbiased sample of people and asking who is cuter between the two, eliminating in this way the random influences (positive or negative) on the istinctive cuteness reaction caused by cultural bias or personal experiences, because those should be distributed equally and then cancelling each other, while the genetic bias sh... (read more)