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Educability: a field of research in ongoing human evolution
Jean Hiernaux
Educability: a Field of Research in OngoingH u m a n Evolution
Equipe d'Ecologie Humaine, Laboratoire d'Anthropologie Biologique, The place of research of educability within the study of human variation Universitg Paris 7, Tour 16, 2 Place Jussieu, 75251 Paris Cedex 05, France and evolution is defined. Educability of physiological functioning particuKeywords: learning, edueability,
human ecology, energy expenditure, walking, Alexander Technique.
larly interests the human biologist. The program of a study (now in progress) on the educability of energy expenditure during walking is outlined.
Journal of Human Evolution (1985) 14, 371-374
Anthropobiology (or h u m a n biology) is devoted to the study of human biological variation. This apparently circumscribes its scope within the field of anthropology: human variation in its broadest sense. What the term "biological" covers, however, does not a p p e a r to be viewed to date in a uniform way. Some tend to identify it with "genetical". This is misleading except when explicit. Observed biological variation is variation of the phenotype. Only some traits, or aspects of traits, such as the qualitative aspect of blood groups, are completely determined by the genotype. Variation in other traits results from the interaction of genotype and environment, or depends entirely on environmental variation. Genetic variation can explain no more than a part of biological variation, Together with testing different hypotheses about the mode of transmission of a given trait, genetic epidemiology aims at answering the following question: "Which part of the trait's variation is determined by genetic diversity and which part by environmental diversity?" Unless it is proven that the results are of a general nature, the answer derived from a specific study is valid only for that case: a specific breeding population living in specific conditions. Another line of study focuses on phenotypical plasticity, particularly by investigating the qualitative and quantitative differences between genetically similar h u m a n groups living in different conditions. By varying the duration of the diverse environmental influences and the ages during which they occur, such studies try to assess three points: (1) to what extent the environmental effect is restricted to the growth period; (2) to what extent the adult remains plastic; and (3) to what extent previous environmental effects are reversible in the various age groups. Since studies of plasticity deal with the interactions between a species and its environment(s), they fall under the heading of ecology. Some of the questions they try to answer can be formulated in similar terms, independent of the species concerned; for example, the question to what extent do adverse conditions stunt the growth process may be asked for a species of trees or for rats, as well as for h u m a n beings. However, in some major respects the autoecology of our species (human ecology) differs from that of others. One of these is the importance, in the h u m a n context, of learning as a means of coping with environmental variation. As I have developed elsewhere (Hiernaux, 1982) there are strong arguments for predicting that, if human evolution is to progress in the near future, it will do so much less at the genetic level but rather at the phenotypical level, involving a fuller use of the h u m a n capacity for cultural change. Since learning is the way by which cultural 0047-2484/85/04037l + 04 $03.00/0
(~) 1985 Academic Press, Inc. (London) Limited
372
j. HIERNAUX
innovation is transmitted, studying the quantitative effect of the use of the human capacity to learn on the phenotypic expression of a certain trait or function constitutes a research theme of great theoretical and practical interest. This theme can be accepted as belonging to the field of human ecology, but also to that of anthropology. The current subdivision of the study of man into discrete disciplines is largely a matter of convenience; no theory of human variation and evolution can be conceived which would disregard the interactions of the individual and its environment, including the sociocultural environment. The research field just defined might be labelled "educability". Its problems include such questions as: " T o what extent can the expression of a given trait be influenced by learning?" and: "How do different methods of learning compare in their efficiency to modify certain phenotypical traits?" Since educability represents just one sector of phenotypical plasticity, its methodology will involve the comparison of individuals and populations submitted to quantitatively and qualitatively different educational pressures, and include both cross-sectional and longitudinal studies. Learning can influence aspects of mental functioning, behaviour, and physiological functioning. All these being manifestations of life, their study might be labelled "biology" in its broadest etymological sense. However, according to the category of traits which are studied, the competent specialist will call him/herself a psychologist in the first instance, and an ethologist in the second. Only in the case of physiological variables wilt the study be unquestionably labelled "human biology", whatever specialization is claimed by the researcher: anthropobiology, physiology (in an anthropological perspective), human biological ecology, nutrition, or biological ergonomy. This subdivision of the scientific field should not obscure the integrity of the research on educability. Separate studies of mental functioning, behaviour, and physiological functioning represent only different aspects of a single integrated whole, the living person. In this issue dedicated to John Huizinga, it is relevant to note that he is one of the few anthropobiologists who introduced a consistent set of physiological measurements in their regular program of research on non-industrialized populations. Since years, he measured, in his African studies, blood pressure, heart rate, forced vital capacity, forced expiratory volume in one second (as reviewed by Huizinga, 1977) and aerobic power (Huizinga & Hooijen-Bosma, 1978), all in their functional relation to energy expenditure, one of the key variables of ecology. In a prospect of the future of human biology in our changing world (Huizinga, 1978), he stressed the importance of knowing the way in which the available energy is utilized, and added: "Much of this remains rather theoretical and future studies should be directed at a better understanding of energy flows" (p. 472). One such study was started in 1984 by a team of three researchers (Silvia Elizondo, Marianne L6vy and myself). It aims at a better understanding of the educability of the amount of energy expended in performing a given work. The activity under study is one common to the everyday life of nearly all human beings: walking. More precisely, the ultimate question is: to what extent can learning minimize the energy expended in walking a specific distance? This matter has individual as well as social implications, even in those cases where food is abundant and no need is felt to reduce the energy expenditure in order to reduce food requirements. Using more superfluous energy in moving the body implies unnecessary contraction and strain, a psychophysical condition which is likely to induce an earlier and stronger wear and tear of the muscles and joints, and to be accompanied by a feeling of discomfort. The toll of such a mis-use of the self might be high for the individual in
RESEARCH
ON
EDUCABILITY
373
terms of uneasiness and degenerative diseases, and for the society in terms of the social cost of illness and absence from work. The learning method tested is the Alexander Technique, which claims to teach how to perform any movement without using more than the necessary muscular energy. F. Matthias Alexander developed it through tenacious and rigorous experimentation on himself, before teaching it to others. His book The Use o f the S e l f ( A l e x a n d e r , 1932) gives a full account of his research. Later in his life he started to educate teachers in his method, who in turn taught and eventually transmitted it to a further generation of teachers. One of these second generation Alexander teachers presently gives instruction to both pupils and candidates for the teachership in Paris. This gives us the opportunity to compare persons at different levels of mastering the method, and to follow their progress, by comparing and following the amount of energy they expend in walking, as measured by indirect calorimetry. However , finding that energy expenditure decreases with progress in learning the method would not necessarily prove an increasing skill in economizing the energy expended in walking. Such an effect might result from the method acting on any other factor of energy expenditure, by reducing body weight for example. Testing the educability of energy expenditure requires quantification of the influence of such other factors; the test could then be carried out on the residuals of multiple regression equations in which energy expenditure is the dependent variable. Accordingly, the first stage of our program aimed at obtaining a matrix of correlations between energy expenditure in walking and a large array of possible factors involved, in order to apply multiple regression and path analysis to the data. These were collected in 1984 for samples of nearly 100 female and 100 male adults, most of them students or members of the staff of the Universit~ Paris 7. The recorded variables can be classified into five categories. The physical environment was represented by air temperature and humidity (air movement was permanently negligible in the indoor corridor where the participants had to walk). Behavioural traits included the habitual consumption of alcohol, coffee or tea and drugs, smoking habits, and sport practice. Somatometry dealt with body mass, size and proportions, and indicators of body composition. Personality traits were scored by using Gough's Adjective Check List as adapted to French-speakers by Gough & Gendre (1982). Energy expenditure was estimated from the reading of oxygen consumption on a portable instrument, the Oxylog. The participants walked at their spontaneous pace, which was also recorded. Individual pace, rather than a fixed speed, was selected, because a person tends to adopt an optimal walking speed in such a way that energy expenditure per unit distance is at a minimum (Ralston, 1958). Unfortunately, no results can yet be presented, because the analysis of the data has only just started. Reports on the progress of the investigation will appear in due course. The study outlined here illustrates some of the above general considerations: it involves many disciplines, and can be described under several labels. Such a fate is common to many studies of human biology, due to the peculiarities of human autoecology. By its transdisciplinary character, the human biological (or anthropobiological) approach to human variation remains irreducible. References
Alexander, F. M. (1932). The Use of the Self New York: Dutton. Gough, H. G. & Gendre, F. (1982). Manuel de la Liste d'Adjectifs [Adjective CheckList (A.C.L.)]. Paris: Centre de PsychologicAppliqu~e.
374
J. HIERNAUX
Hiernaux, J. (1982). Man in the Heat, High Altitude, and Society. Springfield, Ill.: Charles C. Thomas. Huizinga, J. (1977). A comparative survey of African people living in the northern semi-arid zone: a search for a baseline. In (G. A. Harrison, Ed.) PopulationStructureand Human Variation, pp. 241-271. Cambridge: C.U.P. Huizinga, J. (1978). Human biology in a changing world. Journal of Human Evolution 7, 469-473. Huizinga, J. & Hooijen-Bosma, E. G. (1978). Predicted aerobic power in the Bozo; experiences with the step test in Mali (West Africa). CollegiumAntropologicum2, 179-187. Ralston, H.J. (1958). Energy-speed relation and optimal speed during level walking. InternationaleZeitschri~fi~r Angewandte PhysiologicEinschlieszendArbeitsphysiologie 17, 277-283.
Educability: a Field of Research in OngoingH u m a n Evolution
Equipe d'Ecologie Humaine, Laboratoire d'Anthropologie Biologique, The place of research of educability within the study of human variation Universitg Paris 7, Tour 16, 2 Place Jussieu, 75251 Paris Cedex 05, France and evolution is defined. Educability of physiological functioning particuKeywords: learning, edueability,
human ecology, energy expenditure, walking, Alexander Technique.
larly interests the human biologist. The program of a study (now in progress) on the educability of energy expenditure during walking is outlined.
Journal of Human Evolution (1985) 14, 371-374
Anthropobiology (or h u m a n biology) is devoted to the study of human biological variation. This apparently circumscribes its scope within the field of anthropology: human variation in its broadest sense. What the term "biological" covers, however, does not a p p e a r to be viewed to date in a uniform way. Some tend to identify it with "genetical". This is misleading except when explicit. Observed biological variation is variation of the phenotype. Only some traits, or aspects of traits, such as the qualitative aspect of blood groups, are completely determined by the genotype. Variation in other traits results from the interaction of genotype and environment, or depends entirely on environmental variation. Genetic variation can explain no more than a part of biological variation, Together with testing different hypotheses about the mode of transmission of a given trait, genetic epidemiology aims at answering the following question: "Which part of the trait's variation is determined by genetic diversity and which part by environmental diversity?" Unless it is proven that the results are of a general nature, the answer derived from a specific study is valid only for that case: a specific breeding population living in specific conditions. Another line of study focuses on phenotypical plasticity, particularly by investigating the qualitative and quantitative differences between genetically similar h u m a n groups living in different conditions. By varying the duration of the diverse environmental influences and the ages during which they occur, such studies try to assess three points: (1) to what extent the environmental effect is restricted to the growth period; (2) to what extent the adult remains plastic; and (3) to what extent previous environmental effects are reversible in the various age groups. Since studies of plasticity deal with the interactions between a species and its environment(s), they fall under the heading of ecology. Some of the questions they try to answer can be formulated in similar terms, independent of the species concerned; for example, the question to what extent do adverse conditions stunt the growth process may be asked for a species of trees or for rats, as well as for h u m a n beings. However, in some major respects the autoecology of our species (human ecology) differs from that of others. One of these is the importance, in the h u m a n context, of learning as a means of coping with environmental variation. As I have developed elsewhere (Hiernaux, 1982) there are strong arguments for predicting that, if human evolution is to progress in the near future, it will do so much less at the genetic level but rather at the phenotypical level, involving a fuller use of the h u m a n capacity for cultural change. Since learning is the way by which cultural 0047-2484/85/04037l + 04 $03.00/0
(~) 1985 Academic Press, Inc. (London) Limited
372
j. HIERNAUX
innovation is transmitted, studying the quantitative effect of the use of the human capacity to learn on the phenotypic expression of a certain trait or function constitutes a research theme of great theoretical and practical interest. This theme can be accepted as belonging to the field of human ecology, but also to that of anthropology. The current subdivision of the study of man into discrete disciplines is largely a matter of convenience; no theory of human variation and evolution can be conceived which would disregard the interactions of the individual and its environment, including the sociocultural environment. The research field just defined might be labelled "educability". Its problems include such questions as: " T o what extent can the expression of a given trait be influenced by learning?" and: "How do different methods of learning compare in their efficiency to modify certain phenotypical traits?" Since educability represents just one sector of phenotypical plasticity, its methodology will involve the comparison of individuals and populations submitted to quantitatively and qualitatively different educational pressures, and include both cross-sectional and longitudinal studies. Learning can influence aspects of mental functioning, behaviour, and physiological functioning. All these being manifestations of life, their study might be labelled "biology" in its broadest etymological sense. However, according to the category of traits which are studied, the competent specialist will call him/herself a psychologist in the first instance, and an ethologist in the second. Only in the case of physiological variables wilt the study be unquestionably labelled "human biology", whatever specialization is claimed by the researcher: anthropobiology, physiology (in an anthropological perspective), human biological ecology, nutrition, or biological ergonomy. This subdivision of the scientific field should not obscure the integrity of the research on educability. Separate studies of mental functioning, behaviour, and physiological functioning represent only different aspects of a single integrated whole, the living person. In this issue dedicated to John Huizinga, it is relevant to note that he is one of the few anthropobiologists who introduced a consistent set of physiological measurements in their regular program of research on non-industrialized populations. Since years, he measured, in his African studies, blood pressure, heart rate, forced vital capacity, forced expiratory volume in one second (as reviewed by Huizinga, 1977) and aerobic power (Huizinga & Hooijen-Bosma, 1978), all in their functional relation to energy expenditure, one of the key variables of ecology. In a prospect of the future of human biology in our changing world (Huizinga, 1978), he stressed the importance of knowing the way in which the available energy is utilized, and added: "Much of this remains rather theoretical and future studies should be directed at a better understanding of energy flows" (p. 472). One such study was started in 1984 by a team of three researchers (Silvia Elizondo, Marianne L6vy and myself). It aims at a better understanding of the educability of the amount of energy expended in performing a given work. The activity under study is one common to the everyday life of nearly all human beings: walking. More precisely, the ultimate question is: to what extent can learning minimize the energy expended in walking a specific distance? This matter has individual as well as social implications, even in those cases where food is abundant and no need is felt to reduce the energy expenditure in order to reduce food requirements. Using more superfluous energy in moving the body implies unnecessary contraction and strain, a psychophysical condition which is likely to induce an earlier and stronger wear and tear of the muscles and joints, and to be accompanied by a feeling of discomfort. The toll of such a mis-use of the self might be high for the individual in
RESEARCH
ON
EDUCABILITY
373
terms of uneasiness and degenerative diseases, and for the society in terms of the social cost of illness and absence from work. The learning method tested is the Alexander Technique, which claims to teach how to perform any movement without using more than the necessary muscular energy. F. Matthias Alexander developed it through tenacious and rigorous experimentation on himself, before teaching it to others. His book The Use o f the S e l f ( A l e x a n d e r , 1932) gives a full account of his research. Later in his life he started to educate teachers in his method, who in turn taught and eventually transmitted it to a further generation of teachers. One of these second generation Alexander teachers presently gives instruction to both pupils and candidates for the teachership in Paris. This gives us the opportunity to compare persons at different levels of mastering the method, and to follow their progress, by comparing and following the amount of energy they expend in walking, as measured by indirect calorimetry. However , finding that energy expenditure decreases with progress in learning the method would not necessarily prove an increasing skill in economizing the energy expended in walking. Such an effect might result from the method acting on any other factor of energy expenditure, by reducing body weight for example. Testing the educability of energy expenditure requires quantification of the influence of such other factors; the test could then be carried out on the residuals of multiple regression equations in which energy expenditure is the dependent variable. Accordingly, the first stage of our program aimed at obtaining a matrix of correlations between energy expenditure in walking and a large array of possible factors involved, in order to apply multiple regression and path analysis to the data. These were collected in 1984 for samples of nearly 100 female and 100 male adults, most of them students or members of the staff of the Universit~ Paris 7. The recorded variables can be classified into five categories. The physical environment was represented by air temperature and humidity (air movement was permanently negligible in the indoor corridor where the participants had to walk). Behavioural traits included the habitual consumption of alcohol, coffee or tea and drugs, smoking habits, and sport practice. Somatometry dealt with body mass, size and proportions, and indicators of body composition. Personality traits were scored by using Gough's Adjective Check List as adapted to French-speakers by Gough & Gendre (1982). Energy expenditure was estimated from the reading of oxygen consumption on a portable instrument, the Oxylog. The participants walked at their spontaneous pace, which was also recorded. Individual pace, rather than a fixed speed, was selected, because a person tends to adopt an optimal walking speed in such a way that energy expenditure per unit distance is at a minimum (Ralston, 1958). Unfortunately, no results can yet be presented, because the analysis of the data has only just started. Reports on the progress of the investigation will appear in due course. The study outlined here illustrates some of the above general considerations: it involves many disciplines, and can be described under several labels. Such a fate is common to many studies of human biology, due to the peculiarities of human autoecology. By its transdisciplinary character, the human biological (or anthropobiological) approach to human variation remains irreducible. References
Alexander, F. M. (1932). The Use of the Self New York: Dutton. Gough, H. G. & Gendre, F. (1982). Manuel de la Liste d'Adjectifs [Adjective CheckList (A.C.L.)]. Paris: Centre de PsychologicAppliqu~e.
374
J. HIERNAUX
Hiernaux, J. (1982). Man in the Heat, High Altitude, and Society. Springfield, Ill.: Charles C. Thomas. Huizinga, J. (1977). A comparative survey of African people living in the northern semi-arid zone: a search for a baseline. In (G. A. Harrison, Ed.) PopulationStructureand Human Variation, pp. 241-271. Cambridge: C.U.P. Huizinga, J. (1978). Human biology in a changing world. Journal of Human Evolution 7, 469-473. Huizinga, J. & Hooijen-Bosma, E. G. (1978). Predicted aerobic power in the Bozo; experiences with the step test in Mali (West Africa). CollegiumAntropologicum2, 179-187. Ralston, H.J. (1958). Energy-speed relation and optimal speed during level walking. InternationaleZeitschri~fi~r Angewandte PhysiologicEinschlieszendArbeitsphysiologie 17, 277-283.