In this Symposium we are to discuss biological and social aspects of race. This is, of course, a tender topic, in dealing with which I feel strongly that we must all take especial care to express our ignorance when we are ignorant. Especially is this so in the most sensitive area of the topic, the question whether or not differences between racial groups in so-called mental abilities have an innate genetic component or not. I hope to convince you that nobody knows the answer to this question, and that in present circumstances it is impossible to know or even to foresee with certainty that it will ever be possible to know. Hence, whoever speaks as if he knows that such a racial difference is genetic, or whoever speaks as if he knows that such a racial difference is not genetic, is showing a bias that cannot be justified by the facts. Both they who say the differences are genetic and they who say they are environmental or cultural are equally prejudiced.

It is an observed fact that human populations differ in genetic composition. Some of the inherited diversity is due to combined effects of many genes. Although it would be interesting to know the magnitude and nature of the genetic contribution to some characters under polygenic control, such as intelligence or physique, environmental effects may be so great that no genetic analysis is possible—as Thoday has pointed out earlier in this symposium. With other polygenic characters, such as skin colour, the genetic component is more obvious but still difficult to analyse precisely. The number of genes involved, their frequency and dominance have not been established. This is one of the reasons why selective effects on such characters are not readily measured, although they probably exist.

It is both a pleasure and an honour for me to participate in one of the stimulating Symposia arranged by the Eugenics Society. But it was with some diffidence that I agreed to speak on the topic of miscegenation: a topic which is so complex, so illunderstood, so charged with emotion. Yet miscegenation is of obvious interest to all who concern themselves, as members of the Eugenics Society do, with human biology, human society and the future of humanity. It is a topic worthy of study, and a topic which needs to be discussed frankly if myths are to be dispelled, confusion to be reduced, and problems resolved. For miscegenation has been a continuous process since the earliest times: it is nothing new. As my own guru, Professor E. A. Hooton, was fond of saying, ‘When peoples meet they sometimes fight, but they always mate.’

Much of our understanding of the biological differences between races has come with the development of human genetics. Surveys have established the frequencies of genetic characters known to be under the control of single genes and independent of environmental modification; comparisons of these frequencies in different populations have led to the resolution of many of the earlier outstanding problems of affinities between races and, with the support of experimental and associated investigations, to the identification and measurement of the processes that have given rise to race formation. With this information we can begin to appreciate the extent to which apparent differences are due to racial heritage and to environmental influences.

Man's ability to perform his daily round of work is a complex matter and depends upon an optimal function of numerous organs and their integration. Intellectual ability, motivation and emotional stability play a great, and sometimes decisive, role in work performances.

It is possible to summarize our survey under the following four headings:

1. Members of different ethnic groups may react differently to comparable natural (usually complex) situations.

2. Laboratory measurements of various sensory functions of ethnic groups have often been contradictory; and even though some peripheral differences in perception are a priori probable, others may still be caused by cultural differences in cognition, memory content or motivation; these cognitive and memory differences may be best interpreted as differences in individually acquired but group characteristic reafference systems.

Factor analytic studies in Africa are compared with other cross-cultural investigations into the structure of abilities in different ethnic groups. Similarities and differences are noted; and environmental influences on the acquisition of skills are also summarized. A correlational study of wrong answers to a battery of thirty marker tests given to a group of predominantly Mashona students indicates that efficiency skills of numerical facility and memory remain at the first order of factor extraction, reasoning abilities emerge in second-order analysis, while perceptual styles are present in the third-order level. This study is used to hypothesize, in the context of African systems of thought, the existence of a primary thought mode that asserts itself in conditions involving repeated errors.

The session closed with the showing of extracts from films taken at the Olympic Games in Berlin in 1936. The focus in these extracts was on the differing abilities of various racial types, including a number of shots, many of them in slow motion, of the finals competitors in the high jump, the winning jump being of 6 ft 10½ in. Professor Kalmus was invited to make some comments on the Olympics and the athletes who compete in them.

Two different projections of world population for the years 1980 and 2000, viz. the United Nations Medium Variant Projection and Current Fertility Projection, are considered. Both show large increases in world population. When the more developed regions and the less developed regions are considered separately, the major part of the growth is seen to be concentrated in the less developed regions.

The changes in total population expected in the next 40 years (1960–2000) are seen to be very different from changes which have taken place in the last 40 years.

The age structure of the immigrant female population as shown by the 1961 Census was heavily biased towards the young adult age groups, where fertility rates are highest. The birth rate for such a population could be expected considerably to exceed the average for this country as a whole, due to differences in age structure alone. The Census also showed marked differences betwen the fertility rates of different groups of immigrants but suggested that for the most important groups —from the Irish Republic, the Indian sub-continent and the Caribbean—they then amounted to a completed family size of roughly ½ child above the England and Wales average. There were also marked differences in 1961 between the socio-economic structure of immigrant groups; such evidence as there is points to socio-economic factors as playing an important part in explaining the fertility of immigrants, and its possible change over time.

Until very recently physical anthropology has been more or less exclusively concerned with the study of the evolutionary origins of man and with race. During the first half of this century a vast body of literature accumulated describing the physical characteristics of the world's many populations, both past and present, and classifying these populations into races. Innumerable classifications appeared, which not only varied according to their authors' views as to which race a particular population should be ascribed but also, very strikingly, in the number of races that were considered as compounding the human species. Some recognized as few as three or four, others as many as thirty or more. No small effort was spent in searching for methods to ascribe individuals to one race or another and some people were regarded as being more ‘typical’ of a particular race than others.

I was thinking as we went through the first three sessions of this symposium of a difficulty faced by human geneticists which is not faced by those who are concerned with the genetics of plants and animals, and which I do not think has been mentioned—though, certainly, it was implied in Dr Harrison's Galton Lecture.

The geneticist of plants and animals, if he is concerned with wild plants and wild animals, is considering their viability in a particular environment. The geneticist who is concerned with domestic strains is concerned with something which he knows much more precisely. He knows what he wants; he knows that he wants a cow that will give more milk, or a hen that will give more eggs.

When the United Nations Organization was set up in 1945, one of its first intellectual tasks was to define the problem of racism which had been one of the major factors in Hitler's rise to power and the subsequent devastation of Europe. Hence UNESCO asked a group of biologists and social scientists to draw up a statement in 1949. The original statement and a further version in 1951 proved, however, to be ambiguous and unsatisfactory in certain respects and the Director-General of UNESCO therefore called upon biologists to meet separately in Moscow in 1964 and for their meeting to be followed by a meeting of biologists, social scientists and lawyers which would then address itself to the specific sociological problem of racism.

British colonialism in the West Indies bequeathed a number of racial problems to the local societies as they attained independence. The colonial policy of administration in a ‘multi-racial’ social system did little to eliminate ethnic barriers dividing the various groups. A comparison of recent political change in Trinidad and Guyana suggests that the relative size of the various ethnic groups, combined with ecological and ideological differences, have all played an important role in determining the differential degree of conflict these two nations have recently experienced. Political leaders, citizenry and social scientists alike have held diverging views over the nature and future of these 'plural' societies. Some analysts have tended to emphasize the cultural and social cleavages while others have been struck by the apparent capacity of disparate cultural traditions to merge into a unique amalgam.

This paper attempts to analyse some of the local social structural factors accounting for racial attitudes towards coloured settlers, and will concentrate particularly on the way in which the coloured settlement zones, often known loosely as ghettos, promote the formation of racial attitudes and relationships in Britain.

The aim of this paper was to stress the importance of the adaptive cognitive functioning of man in the causation of prejudice. It was felt that this approach has the merits of economy, credibility and testability of explanation which are not always shared by views seeking the psychological causes of intergroup tensions in the evolutionary past of the species or in unconscious motivation. Three cognitive processes were considered from the point of view of their relevance to the genesis of prejudice in an individual: categorization, assimilation, and search for conceptual coherence.

Though the paper was not concerned either with discussing ways to reduce prejudice or with outlining in any detail designs for future research, it is my belief that the general approach adopted here has implications, both for social action and for research, which have not been as yet consistently and fully taken into account.

The first three sessions of this Symposium would, I think, lead one to say that if one tried to arrange man on the basis of biological characteristics one would get a continuum; the papers given in this fourth session have shown the ineradicable, or so far ineradicable, tendency of mankind to split themselves up into discontinuous groups.

I personally believe the study of race relations should always be directed to a practical result, that is to enable one to get over this simple human tendency, and to enable us to live together.