8io LIFE : OUTLINES OF GENERAL BIOLOGY 



between games, which are restricted to mankind, and play, which 

 children share with young animals. For the game has its rules, and 

 demands self -subordination, whereas play is spontaneous and allows 

 of idiosyncrasies and experimentation. From the biological point 

 of view it is clear that human games cannot fully fulfil the function 

 of play. 



According to Groos there is no general "instinct to play"; it is 

 enough to suppose that each type of pla57ing animal has its inborn 

 or instinctive system or pattern of predispositions towards particular 

 types of adult activity, and that the young are peculiarly sensitive 

 to liberating stimuli. Play implies not only susceptibility, but 

 precocity and plasticity. It secures a certain freedom for initiative 

 before habituation sets in. And, as has been said, this is of especial 

 value when the adult life demands considerable versatility. In such 

 cases, the animals that play best are also likely to work best. 



If play is anticipatory of future work, the different kinds of play 

 will correspond to the chief activities of adult life. Many forms of 

 play, at its simplest, are of the nature of experiments in locomotion, 

 as in aimless racing, rival jumping, riotous gambolling, and feats 

 of climbing or of flying. Here one pictures the behaviour of lambs, 

 kids, calves, young antelopes, and chamois, of foals, young squirrels, 

 and young monkeys. On a second line is sham hunting, in which the 

 young animal chases some moving object irrespective of all utility. 

 A leaf blown by the wind or a ball of grass will pull the trigger as 

 effectively as a small animal. The mother sometimes aids and abets, 

 so here play coalesces with education. The kitten's play with the 

 mouse, often absurdly misinterpreted as "delight in torture", is 

 paralleled in many other young carnivores. It is justified in the 

 present by the repetition of pleasurable excitement, and also in the 

 future by the increased dexterity it develops. When the mouse-play 

 is exhibited by cats of mature years, and apart from their education 

 of their kittens, it is probably a relapse into youthful play, such as 

 is illustrated less poignantly in some other adults. In lions the normal 

 play-period extends for well over a year. 



A third form of play is the sham-fight, familiar in puppies. It has 

 been described among lions, tigers, hyaenas, wolves, foxes, bears and 

 other carnivores; among lambs, kids, calves, foals, antelopes, and 

 other ungulates. It is also common among birds. Care must be taken 

 to keep the sham-fight distinct from the combats of rival males, the 

 first hints of which may begin early, as in bull-calves. And even apart 

 from sex, it is not always easy to distinguish the sham-fight from 

 serious combativeness. In his description of the behaviour of two 

 young gluttons, Brehm says that nothing could be more playful; 

 they were hardly at rest for a minute, but every now and then the 

 note of earnest was struck. Very curious, considering the level at 

 which they occur, are the so-called sham-fights which several good 



