injurious effects that do, but do not necessarily, accompany mental work.

Proper air and light, proper posture and physical exercise, enough food and sleep, and work whose purpose is rational, whose difficulty is adapted to one's powers, and whose rewards are just, should be tried before recourse to the abandonment of work itself. It is indeed doubtful if sheer rest is an appropriate remedy for a hundredth part of the injuries that result from mental work in our present irrational conduct of it. 15

The study of the conditions of mental work seems to reveal, in brief, that the conditions of fatigue are essentially physical in character. Given adequate physical conditions, in particular guarding against eyestrain, over-excitement (which means distraction from the work in hand), and loss of sleep, mental work is itself peculiarly unaffected by fatigue conditions. The degree in which mental work can be persisted in depends, therefore, other things being equal, on the individual's own interests, the number and intensity of rival interests which persist during a given piece of mental work, and the habits of mind with which the individual approaches his work.

It is consequently impossible to find any uniform rule for deciding when to stop (mental) work. 'Follow Nature', 'Work as long as you can', 'Work till a decrease in efficiency appears', or any other rule announced for all workers is bound to be wrong. It is unnecessary for most workers to stop when they are bored or sleepy, and it is unsafe for some to work until they are. The best practical rule seems to be to make sure of adequate exercise and sleep, to divide the balance of time reasonably between the duties and pleasures of life, and to work throughout the amount of time due for work, minimizing the natural (physical) checks so far as may be, by securing proper physical conditions, interest and motive, and, for the rest, disregarding them.16

The experimental demonstration that so-called mental fatigue is largely physical in its conditions has thus a dual significance. It indicates how arduous and persistent mental endeavor may be and how wide are the possibilities of intellectual accomplishment. It is an important fact for human life

15 Thorndike, p. 328.

16 Thorndike, p. 329.

that the brain is possibly the most tireless part of the human machine. What seems to be mental fatigue can be materially reduced if the physical conditions under which studying, writing, and all other kinds of mental work are performed are carefully regulated. Another large part of what passes for mental fatigue will be removed if the individual becomes trained to a reflective appreciation of the end of his work. A habit of alert and conscious attention, if it is really habitual, will enable one to persist at work in the face of tempting distractions. Learning to 'tend to business' by an intelligent application to the aims of the work to be done, will be a healthy antidote against that yielding to every dissuading impulse which so often passes for mental weariness.

CHAPTER V

THE GREGARIOUS CHARACTER OF MAN

It is one of man's original tendencies to be with other people, both physically and intellectually, to feel a sense of comfort in their presence, and of uneasiness if too much separated from them in action, feeling, or thought. The 'herd instinct' is manifested by many animals very low in the scale of animal development. McDougall quotes in this connection Francis Galton's classical account of this instinct in its crudest form: "Describing the South African ox in Damaraland, he says he displays no affection for his fellows and hardly seems to notice their existence so long as he is among them; but if he becomes separated from the herd, he displays an extreme distress that will not let him rest until he succeeds in rejoining it, when he hastens to bury himself in the midst of it, seeking the closest possible contact with the bodies of his fellows.1

This original tendency exhibits itself among human beings in a variety of ways. The tendency of human beings to herd together, for which there is evidence in the earliest history of the race, may be observed on any crowded thoroughfare, amusement park, or city. That group life has expanded partly through practical necessity, is, of course, true, but groups of humans tend to become, as in our monster cities, larger than they need be or can be for economic efficiency.

The fascination of city life has not infrequently been set down to the multiplicity of opportunity offered in the way of companions, amusements, and occupations after one's own taste. But the fascination has clearly a more instinctive basis, the desire to be with other people. Many a man, as has been pointed out lives in a large city as unsociable and secluded a life as if he were surrounded by miles of mountain or prairie, and yet could not be happy elsewhere. Anyone who has failed to be amused by a really good comedy when the theater was

1 McDougall: Social Psychology, p. 84.

comparatively empty, or in the presence of thousands of others hugely enjoyed a second-rate baseball game, or gone down to the crowded Fifth Avenue shopping district to get what he could have purchased on a sidestreet uptown can appreciate how instinctive is this undiscriminating desire for companionship.

The native intensity of this desire is what makes rural isolation, on the other hand, so unsatisfactory. The bleakness of New England country life as pictured in Edith Wharton's 'Ethan Frome', or in some of Robert Frost's 'North of Boston' is due more than anything else to this privation from companionship. Perhaps nothing better could be said for the rural telephone, the interurban trolley, and the cheap automobile than that they make possible the fulfillment of this normal human longing to be near and with other people in body and spirit. The horror which makes it practically impossible in civilized countries to legalize punishment by solitary confinement and the nervous collapse which such confinement brings about are indications of how deep-seated is this desire.

The tendency to find comfort in the presence of one's fellows and uneasiness if too much separated from them, is as pronounced in the sphere of moral and intellectual relations as it is in the case of merely physical proximity. We like to be one of a crowd in our opinions and beliefs, as well as in our persons. There is hardly anything more painful than the sense of being utterly alone in one's opinions. Even the extreme dissenter from the accustomed ways of thinking and feeling of the majority is associated with or pictures some little group which agrees with him. And, if we cannot find contemporaries to share our extreme opinions, we at least imagine some ideal group now or in posterity to share it with us.

The painfulness of being alone in a belief is well illustrated in De Maupassant's story called 'The Piece of String'. A poor peasant, accused of stealing a purse, protests that what passersby saw him pick up from the road was only a piece of string. Nobody believes him. He knows he is innocent, but even after he is cleared, he cannot refrain from forcing upon every passer-by his pathetic plea for belief: "It was only a piece of

string; it was only a piece of string." When people refuse still to believe him, he almost loses faith in himself. This is only one instance of how people's confidence in their own abilities is to a large degree affected by other people's opinions. Courage, melancholy, despair are often unwarrantably contagious. Much of our social life exhibits gregariousness in belief. In the words of Mr. Trotter:

The function of conversation, it is to be supposed, is ordinarily regarded as being the exchange of ideas or information. Doubtless it has come to have such a function, but an objective examination of the function of ordinary conversation shows that the actual conveyance of ideas takes a very small part in it. As a rule, the exchange seems to consist of ideas which are necessarily common to the two speakers and are known to be so by each. The process, however, is none the less satisfactory for this; indeed, it seems even to derive its satisfactoriness therefrom. The interchange of conventional lead and return is obviously very far from being tedious or meaningless. They can, however, have derived very little from it but the confirmation to one another of their sympathy, and of the class or classes to which they belong.2

'The herd instinct', like all the other of man's original tendencies, is educable. It can be trained to respond to groups of various sizes and kinds. In its simplest manifestation it tends to be aroused by the family, but in the history of civilization the group tends progressively to enlarge. The family, the town, the nation-the gregarious instinct may be educated to respond to these ever-widening groups. The intensity and controlling power of the instinct over our actions seems to vary with the degree of intimacy and intercommunication between the individual and the group. In primitive society it is most intense among the family and clan, and the family still remains in civilized society, certainly in rural districts, a very closely knit primary group. But as intercommunication. widens, a sense of attachment to and solidarity with a larger group begins to make itself felt. That intercommunication is largely important in extending the group in response to which the herd instinct may be aroused is well illustrated by the utter lack of national group feeling, exhibited during the

Trotter, L.: Herd Instinct, pp. 118-119.