What is the latest theory of why humans lost their body hair?

 
This is the question asked in this month's issue of Scientific American. Mark Pagel, head of the evolutionary biology group at the University of Reading in England and editor of The Encyclopedia of Evolution gives three adaptationist explanations.

Now, here's the question of the day for all you adaptationists. Why didn't he mention neoteny? Do you think it's because he has carefully reviewed all the evidence and reaches the conclusion that there's more data to support running on the savannah?