Its a term that I came across recently in a conversation. It means the tendency of delayed maturity in the offspring of species and is an evolutionary tool which shapes the way a species evolves. The offsprings might perceive an evolutionary advantage in retaining certain characteristics of their adolescence for a longer time and this behavior is selected and propagated down the species.
In humans, this has been used to explain the absence of body hair resembling young primates. And significantly, female characteristics are also explained as a neoteny for the female features resemble that of children.
Pretty cool thoughts but what struck me was that in the modern world, especially here in US, there is also a selection for neoteny in behavior especially vis-a-vis the old world. There seems to be a predominance of playful behavior which resembles the way children behave. While in the old world, people tend to be more respected when they are serious and playfulness and fooling around is looked down upon.
But ofcourse, as they say all work and no play makes jack a dull boy. So play on and select this behavior and I am being dead serious here.