WHY IS HAIR SO APPEALING ? Good question, l o n g answers, evolution ... survival
A newborn baby needs Mother's touch to send signals to the child's brain which enable healthy brain development.
Orphaned babies are placed on a fleece to mimick Mother's touch.
The mechanism is touch receptor nerves in the skin called C-Tactile Afferents,
that mainly respond to a very light, slow touch,(2.5cm/sec), like a Mother's,
and is called KNISMESIS.
The reason hair and touch fetishes sometimes appear to originate before
puberty is that the C-Tactile afferents receptors are present at birth,
(probably before birth too), and they like to be touched,
at a very specific speed of 2.5 centimetres per second, about 1 inch/sec.
A lot of people who did get enough Mother's touch still develop a liking
for hair,(and fur),just because they feel nice, VERY nice.
A child that does not get the touch it needs
will subconsciously try to get it in other ways.
With me it was rolling around naked on a
Sheepskin rug when I was about 6 years old. I'm now 70
and a total hair addict, and I don't much like the word fetish,
liking hair is natural and normal.
So, with help from Science to combine knowledge of knismesis, feelgood endorphins and mindfulness/meditation,
it's possible to amplify pleasure.
The relaxation techniques,(mindfulness/meditation) are needed
for a powerful ecstatic experience because any stress reduces
nerve impulses leading into the brain's pleasure areas.
A light touch de-sensitises the skin very slowly,enabling long distance edging,
with massive endorphin feelgood built up over several hours.
A person with REALLY long hair can touch almost ALL
of their lover's skin at the same time. A powerful technique.
There's several ways to do this:
Long hair
Fur/s 
Multiple partners
ALL 3 !
Or more...
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So for further research ...
C-Tactile Afferents
Knismesis
Endorphins
Edging
Here's a link to a BBC Sounds article on the subject, in plain, non-scientific language.
Either listen to the article or click "Open Transcript" to read it.