Neoteny in literature

I’m trying something new: recreational reading, non-academic literature to get my mind of work at the end of the day. My Platonic soulmate recommended, almost a decade ago now, Still Life With Woodpecker by Tom Robbins. I was very surprised, then, to run into this passage:

“Neoteny” is “remaining young,” and it may be ironic that it is so little known, because human evolution has been dominated by it. Humans have evolved to their relatively high state by retaining the immature characteristics of their ancestors. Humans are the most advanced of mammals – although a case could be made for the dolphins – because they seldom grow up. Behavioral traits such as curiosity about the world, flexibility of response, and playfulness are common to practically all young mammals but are usually rapidly lost with the onset of maturity in all but humans. Humanity has advanced, when it has advanced, not because it has been sober, responsible, and cautious, but because it has been playful, rebellious, and immature.