I.— PHYSIOLOGY. 177 



which compose such a large part of the average environment. Although 

 for general purposes, such as the calculation of mean or average 

 demands, it may be both convenient and useful to assess the data on 

 an average man basis, yet it is the individual variation which controls 

 the actual operating conditions. When we are dealing with the efficiency 

 of the human organism, male and female, we are dealing with indi- 

 viduals whose performance is neither uniform throughout the year nor 

 from week to week, nor even from hour to hour. We have to deal 

 with an organism, as I have already mentioned, which is not only under 

 physical control, but is very responsive to psychic influences — an 

 organism which not only becomes in the course of the day physically 

 'tired,' but which unconsciously is influenced to an enormous extent 

 by its environment, by its ' atmosphere.' Man is, in the main, a 

 psychic chameleon. 



In this connection monotony of work must be considered. The 

 Health of Munition Workers' Committee stated that monotony is 

 ' analogous to, if it does not represent, a fatigue process in unrecognised 

 nerve centres.' It is true that monotonous work, be it light or heavy, 

 may be, as Goldmark maintains, ' more damaging to the organism than 

 heavier work which gives some chance of variety, some outlet for our 

 innate revolt against unrelieved repetitions.' Still, although there may 

 be a close relationship between monotony and fatigue, as generally 

 recognised, they are not identical. The temperament of the operative 

 plays an enormous part in the determining whether or no any particular 

 operation is a monotonous one. Thus a skilled engineer put on to 

 attend an automatic machine which requires the minimum of skilled 

 attention would soon be disgusted with the monotony of the operation 

 even if the pay were good, whereas an unskilled worker, especially if of 

 a lower degree of intelligence, could attend to such a machine without 

 strain. Munsterberg has recorded a number of most interesting 

 examples of this seeming imperviousness to monotony even'on the part 

 of apparently intelligent individuals. Probably, indeed, if the opera- 

 tion is a slow one, or, if quick, one in which the movements are rela- 

 tively simple, the dull individual- — the organism with few trained re- 

 ceptors — and the worker with intelligence above the average, who 

 readily masters the performance and can then let his mind free to 

 speculate on his own private interests, will stand the strain better than 

 the worker of average intelligence. As Munsterberg has shown, it is 

 extremely difficult, if not impossible, for an outsider to determine what 

 a monotonous operation is. It is obvious that if A is interested, let us 

 say, in epigraphy, he will judge that B, engaged in some simple routine 

 stamping or packing job, is employed on a monotonous operation, 

 whereas it would be equally likely that if B were asked his opinion he 

 would candidly state that he would not exchange his interesting work 

 for the dull and monotonous pursuit of A. 



There are many other factors which play a definite and important 

 role in the maintenance of efficiency, such as lighting, heating, ventila- 

 tion, the mode of life led by the woiker outside his definite hours of 

 labour, his housing, &c. Many of these factors have been partially 

 examined. Thus T/eonard Hill has carried out a great deal of valuable 



