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Scientific Working Group for Forensic Anthropology (SWGANTH) 

Sex Assessment 

Issue Date: 06/03/2010 

Revision: 0 

Sex Assessment 

1.0 Principle, Spirit and Intent 

Skeletal remains should be analyzed in an organized manner to assess sex. The most 

appropriate technique(s) for assessing sex should be reliably and objectively applied. 

Tests should be documented in a manner conducive to the replication and verification of 

the work performed. 

2.0 Purpose and Scope 

Sex assessment of skeletal remains is important because the estimation can be compared 

with antemortem records and other information contributing to the identification process. 

In addition, sex assessment serves as a foundation for developing other essentials of a 

biological profile. Conversely, a sound and valid assessment of sex is also dependent on 

accurate assessments of other biological parameters, such as ancestry and age. 

This document outlines practices for assessing sex from skeletal remains. Many different 

methods are used in field and laboratory settings, so the purpose is not to endorse one 

particular method. Rather, it is to establish guidelines that encourage the valid assessment 

of sex. In the absence of specific guidelines or procedures or in the case of conflicting 

procedures, the principle, spirit and intent should be met. 

3.0 Factors in Sex Differences

While almost every adult skeleton exhibits male or female characteristics reflecting 

sexual dimorphism, the validity of sex assessment is affected by several factors: interand intra-population differences, age, and pathological and taphonomic changes. 

3.1 Inter-Population Variation 

There may be differences among populations, so the group on which the standard is 

based should be considered in all applications. When applying size standards, sexual 

dimorphism in one population may be extreme, while in another population the 

differences between the sexes may be slight. In addition to varying degrees of 

dimorphism, populations may differ in size. Applying the standards of a larger, more 

robust group to a smaller, more gracile may yield erroneous results. 
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3.2 Intra-Population Variation 

In addition to inter-population differences, sexual dimorphism may vary within a single 

population. Differences in socio-economic status, for instance, may affect differences 

between the sexes in those groups. Secular change and biomechanical demands on the 

skeleton within a population may also affect the validity of a trait used to assess sex. And 

in all populations, there are outliers representing the extremes of the distributions. 

3.3 Age 

Age can affect the degree of sexual dimorphism and sex assessment. Methods based on 

bone dimensions may be affected by the relative age of the adult.

3.4 Pathology and Taphonomy 

Pathological or taphonomic alterations may preclude the employment of specific sex 

assessment techniques. Alternately, sex predilection of some pathological conditions 

offers insights to sex assessment. 

4.0 Approaches 

Selection and application of sex assessment methods depends on the skeletal elements 

available for examination, their condition/relative degree of preservation and the general 

age of the individual. Analysis of skeletal remains for sex estimation may involve 

different or multiple approaches, including morphological and metric traits. 

4.1 Morphological Traits 

Skeletal differences in morphological traits vary between the sexes by shape, features 

and/or relative size. Methods based on the shape and size, and the presence or absence of 

features of the pelvis are preferred. Other useful elements for morphological assessment 

of sex include the cranium and mandible, although these distinctions are largely due to 

gracility or robusticity. Morphological traits of other elements may reflect sex 

differences, but are usually less reliable. Whatever elements are assessed, employ 

exemplars, identifying multiple traits with marked sexual dimorphism and document 

observations. 

4.2 Metric Assessments 

Metric assessments of sex are based on size and/or shape of skeletal elements and 

dentition. Measurements used in sex estimation generally involve limb bone size and 

articular surface size. Appropriate measuring instruments, standards and/or software are 

employed. Although a single measurement may provide reasonably valid sex estimation, 

multiple measurements and multivariate techniques provide greater reliability in sex 

assessments. 
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5.0 Best Practices 

The following practices are recommended for sex assessment: 

 Sex assessment should be made independently of suspected or presumptive 

identification to avoid bias. 

 When appropriate, use population- and period-specific standards. 

 Assess and measure the maximum number of age-appropriate cranial and 

postcranial variables, emphasizing the most dimorphic elements present, 

especially in the case of fragmentary remains. 

 Document and describe the location of any inconsistent indicators. 

 If an observation cannot be made or a measurement cannot be taken, explain its 

absence: missing, broken, fractured, congenital, pathological, or anomalous. 

 Sex assessment, as well as assessments of other skeletal parameters, should be 

performed, even if samples for DNA analyses will be taken. 

 Express degree of certainty when reporting sex assessments, especially when a 

sex assessment is less than certain, e.g. “male?” 

 When an assessment of skeletal sex is not possible (e.g. partial remains or those of 

subadults), sex assessment by DNA analysis may be helpful. 

6.0 Unacceptable Practices 

The following practices have little or no scientific basis in human osteology or are not 

considered reliable at this time and are therefore not recommended. 

6.1 Sub-Adult Sex Assessment 

It is generally unadvisable to assess sex for fetal/infant/child (under 12 years) remains 

because valid sex assessment techniques are unavailable. In some instances, however, 

valid sex assessment of older adolescents (>14 years) is possible when innominate 

elements (pubis, ischium and ilium) are fused by employing applicable techniques 

established on adults. 

6.2 Assessment of Gender 

Gender (the social expression of the feminine-masculine continuum) is not determinable 

from the skeletal remains alone. Sex, based on genetic differences, is assessed 

anatomically and at the molecular level from skeletal remains.