THE skull arrived in a cardboard box. “It was nothing special,” recalls Rob
Kruszynski of London’s Natural History Museum. What struck him more was the fact
that the police officer carrying the box was out of uniform. “Detectives prefer
not to be conspicuous,” notes Kruszynski who, as a member of the museum’s Human
Origins Group, was unused to cops, crime and contemporary human remains.
The remains in question had been unearthed by builders who were working in a
Cardiff garden. It appeared to be murder, and the police asked researchers at
the museum to help uncover the victim’s identity. Working with colleagues Chris
Stringer and Theya Molleson, Kruszynski took 33 different measurements from the
skull and then used a computer program called CRANID to compared these with the
same measurements on 2500 skulls from over 60 groups of people worldwide. Within
minutes CRANID had revealed that the skull probably belonged to a Caucasian
female of mixed British and non-British descent. This gave the police vital
information about likely skin colour and hair type to add to a facial
reconstruction. Just days after photos of the reconstruction appeared in the
media, the victim was identified as Karen Price, a teenage runaway of Welsh,
Greek-Cypriot, Spanish and American ancestry.
All this happened more than a decade ago. Kruszynski admits he was sceptical
that CRANID could help, but the identification of Karen Price really opened his
eyes. Now he is one of a growing band of researchers using cranial measurements
and comparisons to help pin down the origins of mysterious human remains. It’s a
fast and inexpensive way of shedding light on all sorts of events, from genocide
to the movements of our earliest ancestors.
Advertisement
But many people remain uneasy about looking for racial differences in the
contours of a skull. Craniometry, they point out, was discredited decades ago
because of its associations with eugenics, biological determinism, racism and
the Nazis. Can it live down its seamy past?
Craniometry has its origins in the 19th-century eugenics movement, the
brainchild of Charles Darwin’s cousin Francis Galton. Galton believed that all
our attributes, from beauty to brainpower, are inherited and quantifiable, and
he famously toured Britain, callipers in hand, taking the measure of good
breeding. His techniques were soon being emulated by like-minded scientists. In
the US, physician Samuel Morton used his personal collection of over a thousand
skulls to “prove” that people can be graded from superior to inferior, according
to skull size and shape. His findings? Whites came out on top, blacks at the
bottom and native North Americans in the middle. Craniometry seemed to confer
scientific legitimacy on social reality, and there was no shortage of
researchers willing to take up the challenge to find measurements that just
happened to bolster their own prejudices.
The key flaw in these pioneers’ logic was the assumption that the size and
conformation of a skull represented the quality of the brain within.
Investigators presumed that certain skull parameters correlated with specific
traits, and this allowed them to rank “races” according to attributes such as
intelligence or capacity for civilised behaviour. The great French surgeon and
anthropologist Paul Broca claimed, for example, that flat-faced Europeans were
smarter than Africans with forward-jutting faces, and that women were less
intelligent than men because of their smaller brains. Broca also championed the
“cephalic index”—the ratio of a skull’s breadth to its length—which,
he claimed, showed that long-headed “Nordics” and “Aryans” were physically,
culturally and mentally superior to short-headed peoples such as the Finns and
Basques.
This sort of craniometric nonsense began to lose its cachet at the turn of
the 20th century, when American anthropologist Franz Boas debunked the cephalic
index. By studying immigrants to the US he found that the index varied so widely
within groups of people with similar ancestry—and even over an
individual’s life—that it meant absolutely nothing. The kiss of death for
craniometry came when Nazi eugenicists claimed they could use it as a way of
identifying valuable traits that could be bred into their Aryan race.
These days nobody accepts that you can predict a person’s intelligence or
character by the shape of their skull, so why is craniometry making a comeback?
The truth is that it never really went away. Physical anthropologist William
Howells, now in his 80s and retired from Harvard’s Peabody Museum, has always
firmly believed that craniometry can lead to important scientific discoveries.
“Bill ignored objections to the method and went right on doing it,” says Richard
Wright, a forensic archaeologist from Sydney University. And in 1987, Howells
gave other researchers access to his findings— 70 measurements from each
of 2500 skulls from people around the world. “Bill just asked that we keep in
touch with any interesting findings,” recalls Wright.
Wright realised that with Howells’s measurements and the power of modern
computing, craniometry could become a rigorous technique to help prise open the
secrets of human origins, migrations and identity. So in 1992 he created CRANID.
Using a statistical procedure known as multivariate analysis, CRANID compares
mystery remains with those of people from different regions of the world and
different periods of history. Instead of being limited to comparisons of one or
two variables of dubious quality, as in Broca’s day, researchers can now look
for patterns in the detailed topography of skulls. The analysis indicates which
groups of people are most like the skull under examination. And similar shapes,
claims Wright, usually mean similar origins. “You can tell a skull by the
company it keeps,” he says (see Diagram).
Granted, there are disagreements about which statistical methods are best and
what sorts of problems CRANID and its ilk are best suited to. Still, Wright
argues that results based on so many careful measurements are meaningful and
largely free from the subjective interpretations that used to plague
craniometry. He also denies the charge that scientists who study human skulls
give life and breath to the 19th century notion of “race” and encourage 21st
century racism.
“The material evidence of the skulls discourages racism,” Wright says. “Hide
the skulls and racists can run riot with fanciful and unverifiable morphological
comparisons.” He points out that even in the heyday of craniometric madness some
researchers actually confronted racial prejudice through the objective analysis
of skulls. Meanwhile, a new generation of researchers has emerged, one for whom
Morton, Galton and even the Nazis are remote figures with outmoded ideas. These
contemporary scientists are pragmatic, willing to borrow procedures and ideas
from different disciplines with few preconceptions about them.
But even if craniometry itself is no longer considered provocative, some of
the new findings it has turned up certainly are. Take the study done two years
ago by Jerome Rose from the University of Arkansas on the 9300-year-old remains
of “Kennewick Man”—a skeleton discovered in 1996 in Washington state. It
was first thought to be that of a male of European origin, but subsequent dating
suggested that it belonged to an ancient native American.
When Rose used a statistical technique called linear discriminant analysis to
compare Kennewick Man’s skull with hundreds of others from around the world, he
found that it had most in common with those of the Moriori people from the
Chatham Islands off New Zealand, and the Mokapu people of Hawaii. It bore no
resemblance to modern native American skulls or European ones.
Despite this, a US judge ruled last August that Kennewick Man’s remains
should not go to Samoan chief Joseph Siofele, who had claimed that his people
were the rightful owners. Instead, a previous government ruling stands, and the
remains are to be returned to five native American tribes.
It sounds like legalese but there may be more science behind it than meets
the eye, according to Wright. He recently used CRANID to find Kennewick Man’s
“nearest neighbours” in skull terms, and although the Moriori and Mokapu once
again came out on top, this doesn’t necessarily invalidate the native American
claim, he says. “I am wondering how unusual it is for modern native Americans to
have Moriori and Mokapu nearest neighbours,” he says. He is now checking to see
whether this is the case.
In another study, Wright and Stringer used CRANID to reveal that early modern
human skulls—about 30,000 years old—do not show the patterns of
regionality we see today, but instead share features with humans that lived in
Africa and Israel about 120,000 years ago. “This supports the view that modern
regionality evolved very recently, probably after people got to where we find
them today,” explains Stringer. He sees it as further evidence for the “Out of
Africa” hypothesis, which holds that our species evolved in Africa and migrated
from there to the rest of the world, starting only about 100,000 years ago. The
counter-argument is that our ancestors left Africa between one and two million
years ago, colonised Europe and Asia and then independently evolved the regional
variation we see today.
At the Australian National University in Canberra, biological anthropologist
Colin Groves is also interested in using craniometry to shed light on human
origins. He is set to begin a project with independent Sri Lankan anthropologist
P. Raghavan to expand Howells’s inventory by adding new skull measurements of
both living and prehistoric people from South Asia and Melanesia. Groves
believes this will help settle arguments about the origins of Australian
Aboriginal groups and how they are related, as well as allowing museums to
reassign Aboriginal remains correctly.
Wright, too, is busy filling in gaps in Howells’s database. Along with
Kruszynski, he is collecting measurements from medieval Londoners,
fourth-century Romano-British people, Iron Age Palestinians and the ancestors of
people living on the Indian subcontinent. As well as beefing up the database,
Wright hopes to determine who’s who—or rather whose relatives came from
where—at the medieval burial ground of St Mary Spital at Spitalfields, on
the edge of the City of London.
Research done there in the 1930s suggested that early Londoners were
“peculiarly non-British”, and Wright says that preliminary analysis of 101
skulls of the 11,000 people buried there shows that medieval Londoners were more
like the central Europeans of that period than their Scandinavian contemporaries.
Wright plans to collect measurements from pre-Roman Iron Age people,
Anglo-Saxons and 17th-century Britons to see just how similar the people
buried at Spitalfields are to their Romano-British predecessors.
Meanwhile, Stephen Hughes, a medical physicist at the Queensland University
of Technology in Brisbane, wants to take craniometry even further. Last
September he contacted Wright about using CRANID in tandem with medical imaging
techniques to investigate bodies non-invasively. It could be a valuable tool for
investigating human remains encased in coffins or ice, or where it is important
not to destroy surrounding clothing or tissue.
To see whether it could work, Hughes put the mummy of a 22nd-dynasty Egyptian
priestess—coffin and all—through a CT scanner. His colleague Mark
Barry then created a set of 3D computer images of the skull. Wright took 27
measurements from the skull images and ran them through his latest version of
CRANID, which contains information on 2802 skulls. The program swiftly
identified the skull as that of a female from the ancient Egyptian dynasties,
confirming Hughes’s faith in the idea.
Despite a growing acceptance of craniometry over the past few years, the
science is not without its critics. Anthropologist Alan Thorne from the
Australian National University is one of the most outspoken. He is particularly
doubtful that it can reveal much about the origins and identity of prehistoric
people, simply because there aren’t enough ancient skulls available for
comparison with unidentified remains. Thorne also believes that humans, not
computers, are best at seeing scientific patterns. “All great statements about
human evolution are made by people who understood the anatomy, not just who knew
how to play with measurements,” he says.
But a recent study by Jenny Lumb, a student at University College London and
the Natural History Museum, seems to justify the confidence that Wright and
others have in their programs. Lumb plans to become a crime scene investigator,
and as part of her dissertation she tested the accuracy of various methods of
cranial identification, including two versions of CRANID. She found the latest
version of CRANID, called C4, was most accurate at identifying which of seven
regions test skulls came from, getting it right 78 per cent of the time. “It
would be nice if the success rate were better,” admits Wright. But, he points
out, the probability of correctly classifying the skulls by chance is just 14.3
per cent.
Lumb believes her results show that craniometry can help cast light on human
remains by pinpointing the probable geographical origin of a skull. In
particular, it offers a fast, first step in an investigation, giving experts
immediate leads to follow while they collect further clues. “It is quicker and
cheaper than DNA analysis,” she says. “It’s also more scientific and therefore
probably more accurate than judging the crania by appearance only.” And the
technique is particularly powerful where researchers need to discover the
origins of a group of skulls—from mass graves, for example. Taking average
measurements from a group of skulls increases the chances of an accurate result,
according to Wright. He has spent the past few years investigating war crimes
for the UN, but has not yet had the chance to use CRANID to help identify such
human remains.
Clearly, there is still room for improvement, but Wright and others are sure
craniometry can only improve as more skulls are measured and added to the
database. But whether this once discredited science will ever become mainstream
remains to be seen. Groves, for one, believes 21st-century craniometry will
become a “sharp arrow” in science’s quiver. After all, he says, it could help
answer questions relevant to us all: where we came from, who our relatives are,
and how we fit into the mix of modern humanity.
-
Further reading:
The Mismeasure of Man
by Stephen Jay Gould, Penguin Books (1981) -
Correlation between cranial form and geography in Homo sapiens
by Richard Wright, Oceania, vol 27, p 105 (1991)