Bulletin of the Psychonomic Society1979, Vol. 13 (3),191-193

Facial feature variation: Anthropometric data II

ALVIN G. GOLDSTEINUniversity ofMissouri, Columbia, Missouri 65211

Facial feature variability as a function of age and gender was explored by using publishedanthropometric data (adopted by Goldstein, 1979) collected from several samples of facesof three racial groups. In addition, feature variability was compared to feature importance inface identification. Gender differences in variability were small except for Japanese women'sfaces, which displayed more variability than other samples in survey. Infants' faces might bemore variable than adults ' faces, but measurement problems cloud the issue. Whether featurevariability is related to feature saliency is still unknown because essential information isstill missing.

Using anthropological data obtained from severalpublished sources , Goldstein (1979) documented theextent of variation of facial features across three racialpopulations by reporting coefficients of variation (CY)for a variety of craniofacial features obtained fromJapanese, black, and white individuals. Coefficients ofvariation are derived readily from original measures bydividing standard deviations by their own mean values.The resultant CV is used typically by physical anthro­pologists to, for example, compare the variability oftwo (or more) populations of head circumferencemeasurements whose mean values differ in magnitude.

Goldstein's (1979) main point, that errors in other­race face recognition is not a function of race-relateddifferences in feature variability, was documented bya comparison of CV values from several samples of eachof the three racial populations. The tabulated datacontained additional information pertinent to threeproblems of interest to research workers in facerecognition memory . This article is intended to presenta summary of analyses of CV values asking whetherfeature variability is related to gender, age, and saliencyof features in face identification.

Common sense and space limitation precludereprinting of Goldstein's (1979) extensive set oftabulations. Nevertheless, the findings discussed hereshould be understandable without reference to theoriginal tables (although the interested reader willfmd them helpful). In the remainder of this article,reference to "Table I" or "Table 2" will be employedonly to identify the location of data under discussion ,and this reference identifies the two tables in the originalarticle (Goldstein, 1979).

The author expresses his appreciation to Michael Robbins,James Gavan, and A. T. Steegmann,Jr. for their help in the initialstages of this project, and to June Chance for her critical readingof an earlier draft of this paper.

FACIAL FEATURE VARIATIONIN MEN AND WOMEN

The literature of face recognition research occa­sionally refers to sex differences in recognizability, but 'the problem is as elusive as the solution because stabledifferences are difficult to demonstrate. Although nocount is implied , face recognition performance dataseem to favor women's faces, but this conclusion shouldbe viewed with more than the usual amount of caution.However, if women's faces are easier to remember,perhaps this advantage is gained because women's facialfeatures are more variable than men's. Accordingly,feature variability in men and women was explored bycomparing CV values of Japanese and white men andwomen . Comparisons with black men and women wereomitted because corresponding CV values were solimited in number.

Twenty-seven craniofacial measures, obtained fromsix populations of Japanese men and women (nativeJapanese , emigrants to Hawaii, and offspring of theseemigrants) made possible 81 male-female comparisons.'In 53 of these, or 65%, Japanese women's facial featureswere more heterogeneous than Japanese men's faces(Table 1, Columns 3-8). White women's faces barelydiffer from Japanese men's faces in variability, but theyare less variable than Japanese women's faces. Compar­ison of CV values across all samples of white facesindicates that women 's faces might be slightly morevariable than men's , but the overall difference is quitesmall; women's CV values are larger in 21, equal in- 7,and smaller in 16 comparisons with men's samples.In summary, although all differences are small, women'sfaces displayed slightly more variability than men's ,and Japanese women's features were the most variableof all the samples included in this limited survey.Examination of these data and additional CV valuesobtained from a variety of sources (not reported in

Copyright © 1979 Psychonomic Society, Inc . 191 0090-5054/79/030191-03$00.55/0

192 GOLDSTEIN

Table 1 or 2) suggests the conclusion that facial featurevariability is not correlated with gender as a generalrule, but appears to vary from one racial subgroup toanother. But in anyone particular subgroup , a stabledifference in variability favoring one sex or the othermay be found .

SALIENCY OFFEATURE VARIABILITY TOFACE RECOGNITION

From a Darwinian point of view, it could be arguedthat feature variability should be closely related to the"usefulness" of the feature as a discriminant stimulusin everyday face recognition . Stated in another way,the degree of variance of facial features should becorrelated with their ecological importance as discrim­inant stimuli for facial recognition in ordinary interper­sonal interactions. Thus , face recognition should bemore dependent on a feature with a wide rather thana narrow range of variation within a population, andthis prediction should be valid even though nothingis known about the magnitude of change that wouldbe just discriminable. In any case, the CV valuesreported for the three racial groups provide someempirical information, albeit limited in scope, to answerthe question, "which features of the face show thelargest and smallest coefficients of variation?" Althoughmuch of the interpretation of the utility of the extremeCVs is speculative, its inclusion is justified because itsuggests several problems for future research.

Of all the measures shown in Table 1, nose salient(a measure of relative nose protrusion) and lip thicknessare the most variable. On the average, the amount thenose protrudes from nearby facial areas varies by 15%in the population from which these measures weretaken. Unfortunately, nose salient was reported foronly Japanese faces, so there is some reason to wonderwhether measures obtained from other samples wouldproduce equally large coefficients. Since for any singlemeasure across all samples, CV magnitude appears tobe roughly similar, it is probably safe to assume thatnose-salient measures taken on other groups would bequite as large as reported here . In support of thiscontention, it should be noted that many of the largermean coefficients involve the nose; for example , saggitalnose protrusion is the second most variable feature,and this measure has been obtained from a white as wellas a Japanese sample." In contrast, the smaller CV valuesare, with one exception, associated with head shapeand size. The exception, forehead height, is quitevariable; there will be more about this later .

From the small amount of evidence available, itappears that degree of feature variability is only roughlycorrelated with feature saliency in facial identificationtasks and in tasks requiring facial description. Eventhough the nose seems to be one of the most variablefeatures of the face, it does not appear to be important

in facial identification (Ellis, Shepherd, & Davies, 1975 ;Goldstein & Mackenberg, 1966; Lin, 1964; see Davies,Ellis, & Shepherd, 1977, for short review of pertinentliterature). On the other hand, Ellis, Deregowski, andShepherd (1975) report that when describing faces, thenose is mentioned as frequently as lips and eyebrows,a finding that suggests that some features may be salientfor one cognitive process but not for another. Most ofthe research just cited studied full-face stimuli, and inthose studies the nose may have lost its potency as a cuefor identification because it is a three-dimensionalfeature best viewed in profile. Recall that nose protru­sion was the important measure in some of theanthropological data. Only Lin's (1964) investigationspeaks directly to this issue, and she found thatdetection of a missing nose in incomplete pictorialrepresentations of faces was no better in profile than infront-view drawings, but her subjects were 3.5 to5.5 years of age, so the problem is still largely withoutsolution.

Accord ing to the limited sample of data displayedin Table 1, lip thickness might be the most variablefeature of the face. Dimensions within a populationcould vary as much as 21%of the mean values in blacks ,and 15% in whites . (Additional data, not shown here orin the original report, corroborate the accuracy of bothmeasures , but see Footnote I). In spite of its highlevel of variability, the mouth appears to be relativelyunimportant for identification according to somestud ies (Davies et al., 1977; Ellis, Deregowski, &Shepherd, 1975; Fisher & Cox, 1975 ; Goldstein &Mackenberg, 1966), but other investigators reportcontrary findings (Lin, 1964; Seamon, Stolz, Bass, &Chatinover, 1978) .

Forehead height, alluded to earlier, is another featurethat is quite variable. In two studies (Davies et al., 1977 ;Goldstein & Mackenberg, 1966), the forehead area wasdemonstrated to be a salient cue for recognition, butunfortunately, in both studies, foreheads were con­founded with hair and hair lines so that even a tentativeconclusion will have to wait on further data . In stillanother investigation, where faces were described, notrecognized, the forehead was found to be a relativelyunimportant feature, yielding frequencies of report aslow as any feature in that study (Ellis, Deregowski, &Shepherd, 1975). Interestingly, in that study , hair lengthand hair position were mentioned by subjects whendescribing faces three to five times more frequentlythan the forehead, which might imply that it was thehair and not the forehead that was the important cuein the two studies just cited in which both featureswere confounded.

The foregoing remarks have drawn attention toseveral interesting areas of research, but the lack ofpertinent data both precludes a meaningful summarystatement and emphasizes our need for additionalsystematic research.

FEATURE VARIABILITY AND AGE

Goldstein and Chance (1964) speculated thatchildren's faces might be less distinguishable thanadult faces because the younger face is less hetero­geneous than the older face. Implications of thisspeculation were tested with ambiguous success, but theevidence seemed to suggest that face age was unrelatedto degree of discriminability. A direct measure ofheterogeneity is available from eight age-relatedanthropological measurements of the face reportedby Herskovits (1930), and from 11 craniofacial measurestabulated by Miklashevskaya (1966). (Space limitationsprecluded tabulation of these extensive developmentaldata in this and the original article.) Analysis of thederived CV values indicate that feature variability ofthe very young face (1 , 2, and 3 years of age) issurprisingly similar to the variation found in bothteenage and adult faces. In fact, if anything, there wasa slight tendency for the features of very young facesto display more variation than the adult faces, butonce again, this increased variability could be an artifactcaused by errors of measurement (see Footnote 2).In conclusion, examination of CV values in a variety ofsamples suggest that either very young faces may bemore variable than adult's faces or they may be equalto adult faces in physical variability. Overall, women'sand men's faces appear to differ little in feature hetero­geneity, except for the unusual variability found inJapanese women's faces. Finally, whether there is indeeda relationship between a features' variability and itsimportance or usefulness in face identification is stillvery much an open question.

REFERENCES

DAVIES, G., ELLIS, R., & SHEPHERD, J. Cue saliency in facesas assessed by the "Photofit" technique. Perception, 1977, 6,263·269.

FACIAL FEATURE VARIATION 193

ELLIS, R. D. , DEREGOWSKI, 1. B., & SHEPHERD, J. W. Descrip­tions of white & black faces by white & black subjects . Intema­tionalJoumal of Psychology, 1975, 10, 119-123.

ELLIS, R. D., SHEPHERD, J. W.,& DAVIES , G. M.An investigationof the use of the Photofit technique for recalling faces. BritishJournal ofPsychology, 1975, 66, 29-37.

FISHER, G. R. , & Cox, R. L. Recognizing human faces. AppliedErgonomics, 1975, 6, 104-109.

GOLDSTEIN, A. G. Race-related variation of facial features:Anthropometric data I. Bulletin of the Psychonomic Society,1979, 13, 187·190.

GOLDSTEiN, A. G. , & CHANCE, J. E. Recognit ion of children'sfaces. Child Development, 1964, 35, 129-136.

GOLDSTEIN, A. G., & MACKENBERG, E. J. Recognition of humanfaces from isolated facial features: A developmental study.Psychonomic Science, 1966, 6, 149-150.

HERSKOVITs , M. J. The anthropometry of the American Negro.New York: Columbia University Press , 1930.

UN, Y. The perception of human face: A developmental study ofstimulus potency of different facial features . UnpublishedDoctoral dissertation, University of Rochester, 1964.

MIKLASHEVSKAYA, N. M. Growth of the head and face in boysof various ethnic groups in the USSR. Human Biology,1966, 38, 231-250.

SEAMON, J. G., STOLZ, J. A. , BASS , D. R., & CHATINOVER, A. I.Recognition of facial features in immediate memory. Bulletinof the Psychonomic Society, 1978, 12, 231-234.

SHAPIRO, R. L. Migration and environment. New York: OxfordUniversity Press. 1939.

NOTES

1. These data were collected by Shapiro (1939). Only 22measures appear in Table 1; the 5 not shown were omittedbecause corresponding data on white faces were not available .

2. Some caution is advised in the interpretation of thenasal and lip data. Random measurement errors may be inflatingthe nasal coefficients relatively more than those found in otherfeatures because anatomical landmarks on and around thenose are difficult to locate. Also, nasal and lip dimensionsare always small, making them proportionately more influencedby small errors of measurement than would be the case forother, larger features. Up thickness measures have the addedproblem of dimensional "drift" over time; lip thickness canchange as a function of aging, a process that would increasevariability of measurement for any sample composed ofindividuals widely differing in age.

(Received for publication January IS, 1979.)