This UNESCO statement is of considerable historic interest, and is made available in searchable/indexable format by HonestThinking. Scanned pdf is available from


As documented by UNESCO itself, the declaration from 1950 was heavily criticized by researchers who was concerned that "freedom of scientific enquiry is imperilled when any scientific findings or opinions are elevated, by an authoritative body, into the position of doctrines", and UNESCO's approach was compared to "the National Socialists’ notorious attempts to establish certain doctrines as the only correct conclusions to be drawn from research on race, and their suppression of any contrary opinion; as well as the Soviet Government’s similar claim on behalf of Lysenko’s theory of heredity, and its condemnation of Mendel’s teaching." (Fischer). "I can have no part in attempts to solve scientific questions by political manifestoes, as is the practice in Soviet Russia and now at Unesco as well." (Scheidt). The result was the somewhat less tendentious declaration shown below.



See also other papers in the UNESCO-series on race.


For counterarguments, see, e.g., Racial Differences in Intelligence: What Mainstream Scientists Say (1994).




Statement on the Nature of Race and Race Differences


Paris, June 1951



L. C. Dunn (rapporteur)



The reasons for convening a second meeting of experts to discuss the

concept of race were chiefly these:


Race is a question of interest to many different kinds of people, not

only to the public at large, but to sociologists, anthropologists and biologists,

especially those dealing with problems of genetics. At the first discussion

on the problem of race, it was chiefly sociologists who gave their

opinions and framed the ‘Statement on race’. That statement had a good

effect, but it did not carry the authority of just those groups within whose

special province fall the biological problems of race, namely the physical

anthropologists & geneticists. Secondly, the first statement did not, in all

its details, carry conviction of these groups and, because of this, it was not

supported by many authorities in these two fields.


In general, the chief conclusions of the first statement were sustained,

but with differences in emphasis and with some important deletions.


There was no delay or hesitation or lack of unanimity in reaching the

primary conclusion that there were no scientific grounds whatever for the

racialist position regarding purity of race and the hierarchy of inferior and

superior races to which this leads.


We agreed that all races were mixed and that intraracial variability in

most biological characters was as great as, if not greater than, interracial



We agreed that races had reached their present states by the operation

of evolutionary factors by which different proportions of similar hereditary

elements (genes) had become characteristic of different, partially separated

groups. The source of these elements seemed to all of us to be the variability

which arises by random mutation, and the isolating factors bringing about

racial differentiation by preventing intermingling of groups with different

mutations, chiefly geographical for the main groups such as African,

European and Asiatic.


Man, we recognised, is distinguished as much by his culture as by his

biology, and it was clear to all of us that many of the factors leading to the

formation of minor races of men have been cultural. Anything that tends

to prevent free exchange of genes amongst groups is a potential racemaking

factor and these partial barriers may be religious, social and

linguistic, as well as geographical.


We were careful to avoid dogmatic definitions of race, since, as a

product of evolutionary factors, it is a dynamic rather than a static concept.

We were equally careful to avoid saying that, because races were all

variable and many of them graded into each other, therefore races did not

exist. The physical anthropologists and the man in the street both know

that races exist; the former, from the scientifically recognisable and

measurable congeries of traits which he uses in classifying the varieties of

man; the latter from the immediate evidence of his senses when he sees an

African, a European, an Asiatic and an American Indian together.


We had no difficulty in agreeing that no evidence of differences in

innate mental ability between different racial groups has been adduced,

but that here too intraracial variability is at least as great as interracial

variability. We agreed that psychological traits could not be used in classifying

races, nor could they serve as parts of racial descriptions.


We were fortunate in having as members of our conference several

scientists who had made special studies of the results of intermarriage

between members of different races. This meant that our conclusion that

race mixture in general did not lead to disadvantageous results was based

on actual experience as well as upon study of the literature. Many of our

members thought it quite likely that hybridisation of different races could

lead to biologically advantageous results, although there was insufficient

evidence to support any conclusion.


Since race, as a word, has become coloured by its misuse in connection

with national, linguistic and religious differences, and by its deliberate

abuse by racialists, we tried to find a new word to express the same meaning

of a biologically differentiated group. On this we did not succeed, but

agreed to reserve race as the word to be used for anthropological classification

of groups showing definite combinations of physical (including

physiological) traits in characteristic proportions.


We also tried hard, but again we failed, to reach some general statement

about the inborn nature of man with respect to his behaviour toward his

fellows. It is obvious that members of a group show co-operative or

associative behaviour towards each other, while members of different

groups may show aggressive behaviour towards each other and both of

these attitudes may occur within the same individual. We recognised that

the understanding of the psychological origin of race prejudice was an

important problem which called for further study.


Nevertheless, having regard to the limitations of our present knowledge,

all of us believed that the biological differences found amongst human

racial groups can in no case justify the views of racial inequality which have

been based on ignorance and prejudice, and that all of the differences which

we know can well be disregarded for all ethical human purposes.





Scientists are generally agreed that all men living today belong to a

single species, Homo sapiens, and are derived from a common stock,

even though there is some dispute as to when and how different human

groups diverged from this common stock.


The concept of race is unanimously regarded by anthropologists as a

classificatory device providing a zoological frame within which the

various groups of mankind may be arranged and by means of which

studies of evolutionary processes can be facilitated. In its anthropological

sense, the word ‘race’ should be reserved for groups of mankind possessing

well-developed and primarily heritable physical differences from

other groups. Many populations can be so classified but, because of the

complexity of human history, there are also many populations which

cannot easily be fitted into a racial classification.



Some of the physical differences between human groups are due to

differences in hereditary constitution and some to differences in the

environments in which they have been brought up. In most cases, both

influences have been at work. The science of genetics suggests that

the hereditary differences among populations of a single species are

the results of the action of two sets of processes. On the one hand, the

genetic composition of isolated populations is constantly but gradually

being altered by natural selection and by occasional changes (mutations)

in the material particles (genes) which control heredity. Populations are

also affected by fortuitous changes in gene frequency and by marriage

customs. On the other hand, crossing is constantly breaking down the

differentiations so set up. The new mixed populations, in so far as they,

in turn, become isolated, are subject to the same processes, and these

may lead to further changes. Existing races are merely the result, considered

at a particular moment in time, of the total effect of such processes

on the human species. The hereditary characters to be used in the

classification of human groups, the limits of their variation within these

groups, and thus the extent of the classificatory sub-divisions adopted

may legitimately differ according to the scientific purpose in view.



National, religious, geographical, linguistic and cultural groups do not

necessarily coincide with racial groups; and the cultural traits of such

groups have no demonstrated connection with racial traits. Americans

are not a race, nor are Frenchmen, nor Germans; nor ipso facto is any

other national group. Moslems and Jews are no more races than are

Roman Catholics and Protestants; nor are people who live in Iceland or

Britain or India, or who speak English or any other language, or who

are culturally Turkish or Chinese and the lie, thereby describable as

races. The use of the term ‘race’ in speaking of such groups may be a

serious error, but it is one which is habitually committed.



Human races can be, and have been, classified in different ways by

different anthropologists. Most of them agree in classifying the greater

part of existing mankind into at least three large units, which may be

called major groups (in French grand-races, in German Hauptrassen).

Such a classification does not depend on any single physical character,

nor does for example, skin colour by itself necessarily distinguish one

major group from another. Furthermore, so far as it has been possible

to analyse them, the differences in physical structure which distinguish

one major group from another give no support to popular notions of any

general ‘superiority’ or ‘inferiority’ which are sometimes implied in

referring to these groups.


Broadly speaking, individuals belonging to different major groups of

mankind are distinguishable by virtue of their physical characters, but

individual members, or small groups belonging to different races within

the same major group are usually not so distinguishable. Even the

major groups grade into each other, and the physical traits by which

they and the races within them are characterised overlap considerably.

With respect to most, if not all, measurable characters, the differences

among individuals belonging to the same race are greater than the

differences that occur between the observed averages for two or more

races within the same major group.



Most anthropologists do not include mental characteristics in their

classification of human races. Studies within a single race have shown

that both innate capacity and environmental opportunity determine the

results of tests of intelligence and temperament, though their relative

importance is disputed.


When intelligence tests, even non-verbal, are made on a group of

non-literate people, their scores are usually lower than those of more

civilised people. It has been recorded that different groups of the same

race occupying similarly high levels of civilisation may yield considerable

differences in intelligence tests. When, however, the two groups

have been brought up from childhood in similar environments, the

differences are usually very slight. Moreover, there is good evidence

that, given similar opportunities, the average performance (that is to

say, the performance of the individual who is representative because he

is surpassed by as many as he surpasses), and the variation round it, do

not differ appreciably from one race to another.


Even those psychologists who claim to have found the greatest

differences in intelligence between groups of different racial origin and

have contended that they are hereditary, always report that some

members of the group of inferior performance surpass not merely the

lowest ranking member of the superior group but also the average of its

members. In any case, it has never been possible to separate members

of two groups on the basis of mental capacity, as they can often be

separated on a basis of religion, skin colour, hair form or language. It is

possible, though not proved, that some types of innate capacity for

intellectual and emotional responses are commoner in one human group

than in another, but it is certain that, within a single group, innate

capacities vary as much as, if not more than, they do between different



The study of the heredity of psychological characteristics is beset with

difficulties. We know that certain mental diseases and defects are transmitted

from one generation to the next, but we are less familiar with the

part played by heredity in the mental life of normal individuals. The

normal individual, irrespective of race, is essentially educable. It follows

that his intellectual and moral life is largely conditioned by his training

and by his physical and social environment.


It often happens that a national group may appear to be characterised

by particular psychological attributes. The superficial view would be

that this is due to race. Scientifically, however, we realise that any

common psychological attribute is more likely to be due to a common

historical and social background, and that such attributes may obscure

the fact that, within different populations consisting of many human

types, one will find approximately the same range of temperament and




The scientific material available to us at present does not justify the

conclusion that inherited genetic differences are a major factor in producing

the differences between the cultures and cultural achievements

of different peoples or groups. It does indicate, on the contrary, that a

major factor in explaining such differences is the cultural experience

which each group has undergone.



There is no evidence for the existence of so-called ‘pure’ races. Skeletal

remains provide the basis of our limited knowledge about earlier races.

In regard to race mixture, the evidence points to the fact that human

hybridisation has been going on for an indefinite but considerable time.

Indeed, one of the processes of race formation and race extinction or

absorption is by means of hybridisation between races. As there is no

reliable evidence that disadvantageous effects are produced thereby, no

biological justification exists for prohibiting inter-marriage between

persons of different races.



We now have to consider the bearing of these statements on the problem

of human equality. We wish to emphasise that equality of opportunity

and equality in law in no way depend, as ethical principles, upon the

assertion that human beings are in fact equal in endowment.



We have thought it worth while to set out in a formal manner what is

at present scientifically established concerning individual and group



(a) In matters of race, the only characteristics which anthropologists

have so far been able to use effectively as a basis for classification are

physical (anatomical and physiological).


(b) Available scientific knowledge provides no basis for believing that

the groups of mankind differ in their innate capacity for intellectual

and emotional development.


(c) Some biological differences between human beings within a single

race may be as great as, or greater than, the same biological differences

between races.


(d) Vast social changes have occurred that have not been connected in

any way with changes in racial type. Historical and sociological

studies thus support the view that genetic differences are of little

significance in determining the social and cultural differences

between different groups of men.


(e) There is no evidence that race mixture produces disadvantageous

results from a biological point of view. The social results of race

mixture, whether for good or ill, can generally be traced to social




Text drafted at Unesco House, Paris, on 8 June 1951, by:





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