Negroid hair

[Agrippa]

Why have Negroids frizzletop, but Mongoloids not (answer I wrote for a thread on Dodona)

Frizzletop could be selected in extreme situation, in extreme heat. The main reasons why Mongolids dont have it that they dont live in such situations long enough, that they used cultural and physical improvements to stand the heat and that frizzy hair is, especially if very short, what it usually is (just look at pure fil fil haired Khoisanids or frizzy haired Sudanids), sexually rather unattractive.

So its similar to extremely short extremities - f.e. extreme cold environment (fantasy numbers):
sexual disadvantage -2, performance d-a -1, but advantage because of better temperature control + 2 and better resistance against peripheral frostbites + 2 as well = selective win.

For frizzletop the advantage is that shorter hair is generally better for getting rid of heat, the frizzy hair produces a real air cushion (similar to a good hat or tropical helmet f.e.), and air is a bad heat conductor (worse than thick hair). Furthermore if an individual transpires, this air cushion is further cooled better than with Europid or Mongolid hair.

So this was an adaptation to extreme heat before alternative measures of protection were invented by the people in question. Just look at typical South East Asian headgears, Berber and Arab ones, European sun helmets, they all have a similar function and work even better.

But as I said, frizzletop is rather unattractive, especially the short one, a serious disadvantage for females and males as long as a bald head is no fashion - you can see how Negroid women try to compensate with perukes and artificial hair or special cuts - especially those with this extreme frizzletop, short and like a pillow - out of longer you can form artifical hair fashion (compare with Tutsi hair cut f.e. which have no short frizzletop, same with most Aethiopids).

So like many Negrid features, frizzletop can be advantageous in a specific given situation (rather open area, extreme heat, no developed headgear - danger of overheating of the brain - if the brain is bigger (like it was the case in Hominisation), heat is a serious enemy, it needs much energy anyway, but then overheating is another problem, thats why humans transpire - lost their hair protection most likely too because of that. Negrids even went a step further in adaptation to their extreme environment.
But it gives no advantage, just the (aesthetical and even temperature in cold environment) disadvantage, just made for hot areas in situations like above.

Map for the distribution of the typical hair forms (from Saller, after Martin):


Hair form variants (from Saller, after Martin):


Climatic selection (from Schwidetzky, after Biasutti) of dark pigmentation, broad noses and frizzletop:

[Agrippa]

I just translate the terms of the hair form picture, because it explains the hair form distribution map as well, there might be better translations though:
a) straff = tense hair (mostly Mongolid)
b) schlicht = simple hair (Europid) a+b = straight
c) flachwellig = plain wavy (Europid) a+b+c = lissotrich
d) weitwellig = wide wavy
e) engwellig = tight wavy
f) lockig = curly d+e+f = kymatotrich (common in Europid individuals, Weddoids and Australoids)
g) gekräuselt = frizzy
h) locker kraus = loose frizzy
i) dicht kraus = dense frizzy
k) fil fil = fil fil, peppercorn hair
l) spiralig = spiral hair g-l = ulotrich (Negroids, Negritids, Melanesids, Khoisanids etc.)

[Cromlech]

Well, if we want to know the "primitive" kind of hair of humanity, dont we have to look to the hair of australian aborigenes?