98 



i)iscovi:i<v 



square foot, or over twice what is considered normal. 

 Secondly the high speed. This probably is partly due 

 to the good habit of German aircraft engines of working 

 at something above their specified h.p., and partly to 

 the careful streamlining of the machine and the 

 sensible distribution and installation of the engines, 

 which obviously offer very little obstruction to the air. 



Another point is the remarkably low landing speed 

 claimed by the constructors, which, with the very 

 high wing loading and considerable speed of the 

 machine, is stated to be no more than 55 miles an hour. 



Altogether this is a very remarkable machine, 

 probably the most original and most discussed of 

 post-war aircraft, and from which there is much to be 

 learned. Let us hope it is a portent of the future, 

 a forerunner of the giant passenger-carrj'ing aeroplanes 

 that within a few years will be found fiying regularly 

 on the far-reaching air lines of the world. 



Learning in Man and 

 Animals 



By Victoria Hazlitt, M.A. 



Assistant Lecturer in Psijchotogy at Bedford CnUcije, Vni, 

 London 



sily 0/ 



When animal learning is mentioned, the mind is apt 

 to conjure up pictures of a dog sitting with a piece 

 of biscuit on his nose, or of an elephant dancing, 

 or of some other unusual and unnatural feat. It is 

 ■perhaps for this reason that we are inclined to think 

 of the animals' learning process as quite different from 

 our own. In view of this tendency it may prove 

 interesting to institute a comparison between the laws 

 of learning in man and in an animal as low in the scale 

 as a rat. 



Some of the laws of human learning have been studied 

 in experiments with meaningless syllables. These 

 " nonsense" syllables are arranged in series and repeated 

 as uniformly as possible until they are known. The 

 learner endeavours to avoid making associations, as 

 they would introduce an incalculable factor into the 

 results. His work thus consists in forming verbal 

 motor-habits which arc one of the most characteristic of 

 humau activities. One of the rat's most characteristic 

 activities is finding his way about in subterranean 

 labyrinths. In order to study his process of learning 

 under such conditions, a considerable number of 

 experiments have been carried out in which the rat 

 has had to learn his path through a maze. The rat 

 is put at the entrance and is rewarded with food when 



he reaches the end. On the first occasion he usually 

 spends a long time running into blind alleys and re- 

 turning on his path. After a few repetitions, however, 

 he avoids blind alleys and completes his journey in a 

 minimum time. By means of these two methods — 

 the one for human beings, and the other for rats — a 

 number of problems connected with learning have been 

 investigated. 



It has been found that the number of repetitions for 

 learning a long series is disproportionately great when 

 compared with the number for learning a short series. 

 For example, an experimenter who required, on an 

 average, sixteen repetitions in order to learn a series 

 of twelve sjilables required thirty repetitions in order 

 to learn a series of sixteen sj"llables, i.e. an increase of 

 33i per cent, in the number of syllables involved 

 an increase of 87I per cent, in the number of repetitions 

 necessary for learning. The following table shows 

 that the same is true of rats : 



Length of Maze. 



9 feet . 



22 feet . 



27 feet . 



33 feet . 



Number of Repetitions 

 for Learning. 



375 

 973 

 . 180 

 270 



These figures show that any increase in the length of 

 the series to be learned by man or rat necessitates an 

 increase approximately twice as great in the number 

 of times that the scries must be repeated. In the case 

 of human beings, this is true only of learning which is 

 not helped by the meaning of the material to be learned. 

 Meaning and interest tend to reduce the effect of the 

 length of the series. 



Another fact which has been established experi- 

 mentally is that the number of repetitions necessary 

 for learning a given series by heart is affected by the 

 distribution of the repetitions. For instance, a poem 

 w-ill be learnt with a smaller total number of repetitions 

 if these are given once per day than if several are given 

 at a time, and two repetitions on each of twelve days 

 will ensure nearly five times as much being remembered 

 as eight repetitions on each of three days. Experi- 

 ments with rats show that the same law applies to 

 their learning. When they run in a maze three times 

 per day, the total number of repetitions which they 

 require for learning it is almost twice as great as the 

 total number required when thej' run in it only once 

 per day. On the other hand, when the interval 

 between the repetitions is greater than one day, the 

 total number of repetitions increases for both man and 

 rat. Hiunan subjects remembered almost twice as 

 much from eight daily repetitions as they did from eight 

 repetitions given on alternate daj's. Rats who required 

 six repetitions to learn a maze with daily repetition 



