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Distribution of red hair according to age.

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DISTRIBUTION O F RED HAIR ACCORDING TO AGE
NICHOLAS MICHELSON
Department of Anthropology, Columbia University
ONE FIGURE
In a previous investigation* Franz Boas and I were able
to prove that there exists a correlation between the type of
pigmentation of the hair and the rate of graying. Among
whites light hair becomes gray later than that of darker hue.
Earlier research has not dealt with the relative frequency
of red hair in relation to hair of other colors in the same
individual, excepting in so f a r as there are some remarks
pertaining to differences of color of hair of the head and
the body.3
The present study is devoted to the numerical relation of
red hair of the head to that of other hues as well as to
grayness.
The investigation of hair samples showed that in blond,
brown and black hair, red hairs may be found in varying
numbers, sometimes a few scattered hairs only, sometimes
large amounts. When classified according to age, the ratio
of those individuals having any red hair does not seem to be
stable. I have at my disposal hair specimens of 2397 male
whites, clipped from the right temple. Out of that populat,ion
435 persons showed a red component in their hair. The distribution of nationalities of these individuals was : 214 Irish,
l Investigation carried on under the auspices of the Council f o r Social Research.
'The graying of hair. Am. J. Phys. Anthrop., 1932, XVII, 213-228.
For literature see : Chemische und geuetische Uutersuchungen an menschlichen Pigmenten, speziell demjenigen des Haares. K. Saller and F. Maroske.
Zeitschr. f u r Konstitutionslehre, 1933, XVII, 279-317. Also : Pigmentation in
the old Americans, with iiotes 011 graying and loss of hair. Ale; HrdliEka. Am. J.
Phys. Anthrop., V, 110. 2, May, 1922.
407
AMERICAN J O U R N A L OF PFWSICAL ANTHBOPOLOGY. VOL. XVIII, NO.
JANUARY-MARCH, 1934
3
m
a
TABLE 1
84.8
145
98.6
102
--
9.9
17
0.9
1
77.8
ag=
Total
frequency
Per cent of
total for all
~
81.8
1926
___
85.9
~ _ _ _-~
_-
213
- -79.6
___
199
-- _ _
80.9
224
-~
78.6
294
80.7
276
7
5
9.8 1.6
24
9.4
26
9
I 3
1.8
5
I 3
1.1
-__ -_
Z.9
8
3
0.8
1.5
-____
3
5
I
1
2
0.3
1
0.7
1
0.3
0.7
2
1
0.4
1
-
I
__..-
1
1
1
0.8 0.8
0.9
--____
_
1
2
2
1
0.4 0.7 0.7 0.4
1
0.3
0.9
- -_____
:.4
S.8
1.6
0.4
9.8
6.8
1.6
l l
0.9
37 22
__ i7
-__
__
220
4.4
7
3
6
0.s
0.9
0.1
0.8
-______
7
_ 0.4
_
_ _0.4~
__ _
__
._-__
__
__
__ --
9.6 9.6 1.8 1.2
.__ -~1
8 . 4
11
~
11.0 9.6
13
8.1
---
10.5
41
__
13
36
~
0.9
13.0
__
9.0 9.0
~
0.9
-~~-__ _ _ __
1
0.6
6
3
3
23
3.6 1.3 1.3
10.0 81.0 __
__
9
6
1
39
231
187
-__
-
65 and over
6064
55-59
50-54
45-49
40-44
35-39
4
0.6 2.8
1
1.8 _ _
__
2
-__-
60 4.8
171 1.9
109 3.2
1
2
0.4
1
1
0.8
__
1
1.1
-
b.0
-
0.4
9
__-
0.4
9
I I
2125014.9
277 2.8
___-
- OJ
0.7
-
6
0.4
-_ _ 0.4
1
5
2
0.8
_
_
1
~
342 1.9
1
0.8 - _ _ 374 4.3
4
0.4
___
-
~~
1.1
4
1
__ 0.9
0.9 0.7 __
_
-
1
3
1.9 0.4
__
_
-
231 3.0
- ---
0.9
1
- ___~-
1.8
2
-_
1
0.9
1.7
1.7 1.7
-- ___-
~
9.9
1
-__-
91.7
-.
__
1
5-99
35.89 90-94
-
1
-I---
10-14 15.11
i
2
__
5.9
I
55
- -~
Less
than 5
__
_ _ _ _ _ ~
30-34
25-29
20-24
I-
PER OUNT BED HAIR
Per cent of red hair at each age. Red in pcr csnt of red, brown and blaok. Figures in roman are frequencies. Figures in
italics are in per oent of total frequency for the age group
-
409
DISTRIBUTION OF RED H A I R
48 northern Europe, 31 Jewish, 26 German, 11 Scotch, 19
southern and central Europe, and 86 not given. Their distribution seemed to be about the same in all age classes.
The same method of counting was applied as described in
the previous paper. Cases of light hair were too few to give
valid results. For this reason only hair darker than a.standard brown was considered. Doubtful cases in which red and
brown could not be clearly distinguished were not taken into
consideration. The differential count of each hair sample
embraced four combinations: red with or without gray; red
and dark with or without gray. The occurrence of the
hues: red, brown and black as well as of grayness was calculated in per cent. The percentile frequencies were tabnlated.
Figure 1 illustrates graphically the per cent of a given
population (2397 individuals) having any red hair at different ages. This tracing shows an increase of the frequency
of individuals with red hair between 32 and 47 years of age,
then some decrease until the sixty-fifth year, followed apparently by a more rapid decrease.
The same figure contains the average per cent of red hairs
in the total population. It will be noticed that these values
decrease slowly from 22 to 32 years and then seem to rise
slowly.
This relation becomes clearer in the graphical presentation
of the ratios between red and dark, excluding gray hair,
given in the same figure. Unfortunately the number of cases
from which the initial rapid drop is determined is very small.
On the other hand, the steady increase from 32 years on is
well established.
Arranged in larger groups the increase of red hair in proportion to brown and black hair appears clearly also.
TABLE 2
Frequencics among all those having any red hair (455 cases)
Lms than
6 t o SO per cent
SO per cent
A m b iearr
6 p a cent red
rcd
red and over
20 to 39
7.5
4.4
2.1
40 t o 54
11.4
6 .?
2.9
55 and over
8.0
6.3
3.7
410
NICHOLAS MICHELSON
I
Fig.1 Average amount of red i n total population (sum of frequencies of
red divided by the number of those with red, brown and black). Frequency of
individuals having any red (number of those with any red hair divided by
number of those with red, brown and black). Frequency of red for those having
any red hair (sum of frequencies of red divided by total number of individuals
with any red hair).
411
DISTRIBUTION O F RED HAIR
Among all those having any red hair the following ratios
between the frequencies of those with various percentages
of red hair as against the total number of those with any red
hair in the same age group occur:
TABLE 3
Age in Year8
20 t o 39
40 to 54
55 and over
5
Frequencies (435 cases)
Lesr than
5 to 2 9 p e r cent
per cent red
TEd
53.6
54.3
44.4
35.7
32.0
35.0
9 0 per cent
red and over
10.7
13.7
20.6
I t might be assumed that the relative increase of red hair
with increasing age is due to the earlier graying of dark hair.
An attempt to calculate this effect on the basis of the value
for rapidity of graying previously obtained shows that such
an explanation is inadequate.
At this point it must be emphasized that the increase with
increasing age of the frequency of the combined occurrence
of red and black hairs, as found among individuals with more
than 30 per cent of red hair, does not make it clear by what
process this increase is brought about. Red hair is liable to
become darker and we might expect a decrease of redness
among those having any red hair, but the observation shows
the reverse for higher percentages of red. Since the graying
does not account for it there would seem to be some other
reason for the red hair in the older groups.
While classifying the hair samples from the point of view
of pigmentation, it was observed that the series containing
red hairs showed also a certain number of polychrome hairs
which were red at one extreme and black at the other; or in
which red and black were mixed and yielded an impure reddish brown. In other hairs such hues as black and brown or
red and brown occupied different sections of the same hair
shaft. This phenomenon cannot be attributed to fading due
to exposure to light, since there seems to exist a correlation
between the frequency with which one finds a variety of colors
in individual hairs and progressive age. Altogether there
412
NICHOLAS MICHELSON
were 27 persons with distinct black and red sections in the
same hair; 23 persons with red and brown, and 11 persons
with black and brown. Nine persons showed black and red
to combine or almost to fuse into a dirty brown.
Microscopy does not throw any light upon the problem as
yet.
Two examples may be cited, details being superfluous.
First. A hair, about 1 inch in length, was removed in toto
from the author's eyebrow. The proximal part of the shaft
has a reddish hue which turns brown toward the center of
the hair and black at the tip. This hair is somewhat coarse.
TABLE 4
Mixed colors in individual hairs
ED B R O W N AND BLAOB
AGE
YEAEB
Absolute
numbers
?er cent of
total
numbers
Absolute
numbers
'er cent of
total
numbers
1
11
28
11
11
8
70
9.1
15.5
20.9
8.4
16.2
44.4
16.2
0
2
12
7
8
7
36
0
2.8
9.0
5.3
11.8
38.9
8.3
~20-29
30-39
40-49
50-59
60-69
70 and over
All ages
CED AND BLAOK ONLY
ALL MIXED OOLOBS
Absolute
numbers
lpe\tt$t
Of
I
1
13
40
1
18
19
_ 15 _
106
1
9.1
18.3
29.9
13.7
28.0
83._
3
24.5
=I
I
Absolute
numbers
11
71
134
131
68
18 ~
_
433
Dersons
Although the age distribution is not convincing, it suggests an increase of
hairs of mixed color with increasing age. Two samples showing red in combination with blond were not included.
Microscopically there is no difference between the morphological characteristics of a red hair and the red section of
this multicolored hair; nor do the brown or black sections
reveal any deviation from uniformly brown or black hairs.
Second. A hair removed from the temple of a man 90 years
of age. The hair consists of a tapering white part, a central
black and a (basic?) red portion. Microscopically, each section of the hair resembles normal white, red and black hairs
respectively.
Table 4 illustrates the age distribution of persons whose
hair samples displayed a combination of hues in individual
hairs.
~
-
DISTRIBUTION OF RED HAIR
413
What is the explanation of the co-existence of different hues
in a hair? The most plausible assumption would be that we
are dealing with a selective depigmentation. Dark hair must
often contain brown as well as red pigment. If the dark element should become less and less potent in the hair of the
graying person, the presence of the red pigment would become
more apparent. Thus, despite the darkening and graying of
all hairs with the advance in years, a relative increase in
redness would develop in single hairs either as a whole or
in parts of the hair. Until we have learned more about the
chemistry and function of the pigments, we may venture
to advance this theory.
At the close of this presentation I would like to express
my gratitude to Prof. Franz Boas, who directed this work,
and my indebtedness to Miss Bertha Cohen, who executed the
tabulations.
SUMMARY
1. Out of a total of 2397 white adult males from whose right
temple were clipped hair samples, 435 persons showed in
their hair a red component. The series containing red hair
was classified from the point of view of pigmentation. Differential counts of each hair sample were made. The occurrence of the various hues was expressed in percentile frequencies for each age group. There was found an increase
of redness between 32 and 47 years of age, then a slight decrease to the sixty-fifth year; then again an increase up to
the seventieth year of age, followed by a terminal decrease.
The cause of this rhythm is not known.
2. The association of colors in the individual hairs was
studied. Multicolored hairs, rare as they are, seem to increase
in frequency a t certain age groups.
3. It seems plausible, though it cannot be established with
certainty, that dark pigmented hairs contain the red color
component and that the latter becomes more apparent with
the advance of age when the hair undergoes senile changes.
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