Chapter VIMUSICAL INHERITANCE
The whole problem of mental inheritance is in the air, both in the sense that it is current and in the sense that it is relatively intangible. The struggle is best illustrated in the current approaches to the problem of inheritance of intelligence. In this the geneticist has not got far from base, but much has been learned in regard to the nature of the issues involved. In the field of music the geneticist has approached the subject experimentally without understanding the musical life; and the musician has approached the matter practically without being a competent experimenter. The psychologist has certainly not done his duty in clarifying the issues. The most pressing need at the present time is for such clarification. This can not be the work of one man or one generation, but must be achieved through co-operation of both sides in order to clear the way for valid experimentation.
In order to indicate the character of the problem we are now facing, I shall first venture to state some fundamental assumptions upon which probably all competent investigators agree and, second, venture a little way in the direction of identifying concepts of musical life which can be dealt with experimentally.
The mechanism of heredity lies in a single germ cell carrying the character-determining chromosomes which consist of organized chains of genes. In the character and organization of these genes in the fertilized cell we find the complete "blueprint" for the future individual in so far as it is to be determined by heredity. In the twenty-four pairs of chromosomes in the fertilized human germ cell we find the long and diversified heritage of each parent represented through the union of the sperm and the ovum. The selection and the organization of the genes in these chromosomes adequately represent what the future individual can be.
This genetic constitution is modified by the cytoplasm, the supporting part of the cell which is its first environment, and further by the entire embryonic environment. Any changes that take place after the launching of this cell, whether before or after birth, are regarded as environmental. In the embryonic life, this germinating cell develops by processes of cell division and specialization into the complete human organism ready to function more or less immediately after birth. This heritage has fabulous resources in the form of possible facilities for future development. As nature was prolific in the storing and transmission of countless hereditary characters in the genetic constitution, so the equipment of the child at birth is astonishingly prolific in the provision it makes for diversified development of the individual. Development from this stage on must, therefore, of necessity take place through a process of selection and specialization in which certain characters are given right of way and many are subordinated or inhibited by conflicting interests, but the great mass remain relatively latent or dormant. We may assume that superior musical talent is determined in large part by superior musical heredity, and that inferior musical talent or lack of talent may be determined in large part by a correspondingly defective heredity.
The science of heredity in the strictest sense focuses upon the study of the identification and organization of the genes in relation to the determination of characters which shall appear in the genetic constitution and determine future structures and functions of the individual. When the geneticist deals with specific anatomical structures, this relationship is traceable with comparative ease; but when he comes to deal with more or less complicated physiological or mental functions, the tracing of this relationship becomes rather baffling on account of the complexity of the final product.
Turning then to the issues involved in the interpretation of musical inheritance, we must face certain theoretical assumptions. One of them is that a scientific study of musical heredity cannot be pursued on the assumption that mind and body are two distinct entities, each inherited independently. Nor can we hold the old doctrine of psychophysical parallelism. All human geneticsproceeds on the assumption that the human individual is one psychophysical organism. Our musical experience, observation and measurement will therefore represent views from the mental side; our organic studies may be views of the same things from the physical side.
Furthermore, musicality is not one specific human trait but an infinite hierarchy of traits running through the entire gamut of the psychophysical musical organism. To make any progress whatever, the scientist must make the supreme sacrifice of attempting to deal only with specific isolable factors apparently small and remote in themselves. The situation is analogous to that of purely physical features. It is generally admitted that the structure of the physical organism is heritable. But when we show that the color of the eyes of the fruit fly is heritable and that this inheritance takes place in a very complicated way, as has been adequately shown, we have simply identified parts of the structure and function of the genes in one specific feature in the vastly complex physical organism, however fundamental and characteristic this particular feature may be. This analogy applies in principle to the genetic study of the musical life. The crux of the difficulty lies in the identification of heritable factors.
Again we must remember that the musical mind is first of all a normal mind, a normal psychophysical organism ready to begin to function immediately after birth. What we shall look for then in a psychophysical organism is the presence of certain resources especially favorable or especially unfavorable to the normal functioning of the musical mind. We may assume that an average capacity present in the genetic constitution may be adequate for musical purposes but that exceptionally gifted persons require these traits in a correspondingly exceptional degree and that exceptionally unmusical individuals lack essential elements. The most wonderful thing is that a person can come into the world with a musical constitution at all, but the problem of heredity centers around individual differences, and these are more easily approachable than the total function. As in genetic studies of the inheritance of color blindness it has been possible to identify types, so in musical hearing we may look forward to theidentification of types of defect and types of superiority deviating markedly from the normal.
Common observation and reasoning convince us without question that musicality is inherited in some mysterious way and this follows also from general considerations of current theories of biological inheritance. But when it comes to the scientific determination of laws of such inheritance, we face high barriers. Biological laws of inheritance must be established in terms of the genes; a specific biological structure or function must be related to gene organization. Let us call this measurement of the first order. Such measurements are most readily applied to anatomical structure and physiological function in the neuro-muscular organism. This is notably clear in the anatomy and physiology of the ear and its connections. It is equally applicable to the anatomy and physiology of the vocal organs—the bellows, the vibrators and the resonators for voice. It is conceivable, for example, that the length, the mass, the mode of attachment, and the general position and shape of the vocal cords and the mounting of the voice box are heritable characters traceable to genes and referable to musicality as the physical organs for voice.
We can also find relationships to the endocrines, which are in large part the determinants of musical emotionality. Electro-physiology is now giving great promise for the identification of functions in the ear and the brain and its central connections and is establishing interrelationships. Many of the laws of heredity established by measurements of this order probably refer to fundamental biological principles of inheritance in the psychophysical organism as a whole. By a physiological analysis of the sensory, motor, and central factors which operate most significantly in music, the systematist can set up a respectable body of biological facts in regard to musical inheritance which are antecedently probable in terms of the functions of genes and result in the structure and function of the musical organism.
Since the medium of music is sound, we shall look first for an exceptionally responsive or unresponsive ear, including not only the physical ear but the central organs in the nervous system through which it functions. This is basic for two reasons: First,because it determines what stimulation from the world of sound shall enter into the experience of the musical individual to a high degree; and second, because the purely physiological receptivity or organic response to sound acts upon and modifies the state of well-being or ill-being according as the auditory impression is beneficent or noxious in so far as its acts upon our circulation, metabolism, temperature and other organic processes. Such well-being or ill-being is, of course, in part the foundation for the feeling of musical pleasures and pains.
If we would gain a true and comprehensive insight into the nature and extent of role of environment in musical life, we must start with some established facts or reasonable assumptions of what is "given" for environment to act upon. The heritage is the capital fund which the environment invests or squanders. Only by knowing the hereditary contributions can we appraise the environmental contributions. In the study of the fruit fly, for example, the revelations of factors which must be regarded as environmental are quite as significant and essential as the revelations about the original organization of genes. The determination of the limits of heredity is the best means for revealing the functions and possibilities of environment. The music geneticist will therefore learn fully as much about environmental influences as he will about hereditary influences in studying heredity.
The music geneticist can approach many significant aspects of the subject through psychophysical experiments for which we now have fairly standardized procedures. For the present purpose, we may call this measurement of the second order as compared with the anatomical and physiological measurements. It proceeds out of, and is a complement to, the anatomical and physiological foundations and probably represents the most fundamental approach from the psychological and musical points of view. These measurements deal primarily with sensitivity and discrimination on the sensory side and the corresponding processes on the motor side. Among them we may recognize two levels: The simple or elemental, in which a specific mental process is related to arelatively specific organic basis; and the complex, which relates to co-operative functions of the elemental capacities. Of the former we have four; namely, the sense of pitch, the sense of loudness, the sense of time, and the sense of timbre—each of which is correlated with a specific attribute of the sound wave, which is the musical medium. We have basic measurements of the hearing of rhythm, consonance, volume, and sonance—all of which represent relatively complex patterns. Each of these complex functions has a unitary character. Rhythm, for example, is not merely time plus intensity; it possesses a unitary character. Because of the difficulty of dealing with the complex patterns, precedence should be given to the four elemental or basic capacities. Excellence in these capacities contributes toward ear-mindedness, of which the auditory image is the most specific characteristic; but at the present time we have no adequate objective method for the measuring of auditory imagery.
On the motor side we have corresponding measurements of speed and accuracy in the motor control of each of these factors represented in the sound wave; namely, frequency, amplitude, duration, and form.
The term elemental should be used with caution because we never encounter a purely elemental state or process. Even in the very simplest form they are merely more or less specific phases of the mental organism; and at any level at which they are observable they probably involve environmental accretions. It is the old story: We never experience pure sensation but meaningful perception. Yet under the most careful experimental control the identification of such specific functions may be reasonably reliable and have considerable validity.
Adequate measurements of the sense of timbre are new and therefore have not been employed extensively up to date. But the sense of pitch, the sense of time, and the sense of loudness, together with the sense of rhythm and immediate tonal memory, have been used extensively.
The significance of such measurements depends upon the rigidity of the scientific technique and the selection of subjects for experiment. Reliable measurements have been made on avariety of groups and for different purposes more or less related to the problem of inheritance. Studies have been made upon musically precocious children to determine to what degree they were gifted in each of these capacities. All the available blood relatives of six of the foremost musical families in America and a number of such families in European countries have been investigated. These capacities have been measured in selected virtuosi in various fields of music. The measurements have been used for the determination of qualifications for musical organizations and for the analysis of admissions to music schools. Simplified forms of the measurements have been made upon very young children in musical families. Numerous cases of failure in musical education have been investigated and often explained on the basis of presence or absence of these basic capacities. Surveys have been made on groups representing highly-privileged or under-privileged children in the matter of musical facilities. Some of these measures are now a part of the standard tests and measures administered in the public schools so that comparisons can be made with blood relatives, and data are becoming cumulative for scientific comparison of successive generations. Numerous racial studies have been made on a large scale, comparing these capacities, for example, in different degrees of race mixture—as in the transition from pure blacks through mulattoes to whites in a large Negro community, or the comparison of racial groups in Hawaii, the school children in different European countries, Indians with whites, and distinctive races and primitive peoples in different parts of the world.
From this large array of facts certain findings seem to be significant, taking these measurements as a group. First, the sense of pitch, the sense of loudness, and the sense of time reveal no distinctly significant differences in racial groups, in culture-levels, or at age-levels, when adequately measured. In many cases this holds also for the sense of rhythm and tonal memory. This is probably indicative of the fact that the basic capacities for hearing in individuals now living and capable of being tested adequately are physiologically at the same level. This conclusion is in harmony with the observation that these capacities which function in music,function also in the vast varieties of orientation through sound at all levels of man now living. It is also analogous to what has been found in vision. Second, it develops that in each and every one of the groups studied there are enormous individual differences in each of these capacities and that the extent and distribution of these differences do not differ significantly from what we find in the public school children of the United States. Third, where comparisons of capacity and achievement have been made reliably, it has been found that those who have achieved distinction in music have these capacities in a significantly corresponding degree; but much larger numbers of those possessing superior capacity who have not been discovered as musical, either by themselves or in their environment, are revealed. This fact rules out many of the statistical studies of heredity in terms of musical achievement. Fourth, these capacities represent relatively independent factors in hearing. Fifth, marked superiority or inferiority in these capacities is of predictive value for musical achievement and guidance in education.
On the motor side but little progress has been made. Principally because the measurements are laborious, significant elements have not been identified, and moderate motor capacities in speed and action are adequate for most musical achievements. Daily observations reveal that children may be slow and accurate, slow and erratic, fast and accurate, or fast and erratic in various degrees and combinations. It would, however, be of musical significance to discover to what extent and in what manner these traits are inherited from generation to generation.
In view of these discoveries, it is evident that there is some material available for technically rigid genetic interpretation in terms of currently recognized principles of inheritance. All the records on the six foremost musical families of America are available in the confidential files of the Carnegie Institution, at Cold Spring Harbor. Highly reliable measurements on all the students in the Eastman School of Music for the last fifteen years are available. Various public schools have vast cumulative data, and elaborate collections are being worked upon in the Winderen Laboratory, at Oslo. But with the exception of theCarnegie Institution and the Oslo collections, adequate measurements of whole families are absent.
What is needed now is a thoroughly reliable series of measurements on entire musical families and the interpretation of these by a thoroughly competent geneticist in terms of established biological principles of inheritance. It is especially important that both parties shall be competent to take into account the numerous lessons which we have learned from the extensive efforts that have been made in the attempt to measure the inheritance of any mental trait, such as human intelligence. In the human situation we cannot breed successive generations rapidly, as in flies or mice, for experimental purposes. We must, therefore, economize time and effort by taking the most readily available material. For this purpose I have suggested three possible methods (Psychology of Music, McGraw-Hill, 1938). The first is that we start with the highest 10 per cent and the lowest 10 per cent in an adequate sampling of fifth-grade children in a school system and work back by making the same measurements on the available blood relatives of these two groups. In effective organization much time can be saved by making group measurements in a co-operating community, such as a city ward. A second procedure would be to secure an adequate sampling of musicians and measure forward and backward to cover three generations in which the matings of musical and unmusical parents could be traced. A third procedure would be a systematic collection of measurements on school children for a generation or more giving special attention to the showing of blood relatives. We cannot, however, stress too strongly the importance of having these measurements made throughout by an experimenter thoroughly competent in this field and the equally thorough biological treatment of data by scientists thoroughly competent in that specific field. If a biologist wants to start the ball rolling from his point of view, the records in the Eugenics Record office of the Carnegie Institution furnish a fair and reliable sampling.
In proposing this conservative approach through psychophysical measurements, I do not wish to belittle the insight, common knowledge and theories of inheritance which have beenobtained by observation and statistics in terms of musicality as a whole—as in biography, autobiography and letters of great musicians or in the study of musical families. But we are confronted with the fact that these deal largely with unanalyzed situations so completely covered by factors of environment and training as to make them useless for strictly scientific purposes. Nor would I belittle the significance of general traits, such as musical intelligence, creative imagination and the artistic temperament, or facilities for specific skills, such as sight reading, and the memorizing of repertoires. We know a great deal about these and unquestionably have the right to assume that they have an hereditary basis. But scientific studies in heredity may be more properly approached through the simpler and more elementary capacities.
For scientific purposes, we cannot, of course, mix basic measurements and current ratings of musical achievement. There have been numerous approaches to this subject from the musical-achievement point of view, and these have furnished many suggestive leads and probably point to unquestioned facts about the inheritance of musical talent. But the science of genetics rightly rests upon and demands the isolation of specific factors which can be measured; and for that purpose the musical geneticist must, for the present, sacrifice many otherwise interesting approaches from the point of view of rated achievement and be willing to await the laying of foundations of rigidly conducted measurements which can be described, interpreted, and verified.