Neoteny refers to the persistence of juvenile traits, or the retardation of development. For example, it has been speculated that the domestic dog was bred (genetically engineered, as it were) as a neotenous wolf - one whose brain never matures and retains a puppy-like, submissive and thus a trainable, pliable, and friendly mentality. (All domesticated dogs were bred from the wolf, from the Chihuahua to the Huskie.)
Similarly, Stephen Jay Gould speculated that humans may be neotenous chimpanzees. On a bad day, I am quite certain that I am one. Desmond Morris wrote about it.
In fact, the human brain, face, and body demonstrate numerous neotenous traits, the lack of heavy body hair being the most obvious.
The grey matter of the human brain, in particular, shows retarded development even when compared with other apes and primates. Gene Expressions shows the data. (The transcriptome which is referred to is the messenger RNA (mRNA) which, in a timed manner, transcribes the messages from the DNA to make things happen. It's a miracle that it works.)
It is fun to speculate about what the neoteny of the human brain might imply for human development, socialization, learning, and psychology - but it's all speculation. As I have said, the human brain is an ongoing experiment.
