11 Pages


Play, playfulness, or playlike behavior has not proven easy to define or study. But identify­ ing it as a “real” phenomenon is another mat­ ter. Play has been noted in books on animal be­ havior and comparative psychology for many years, as in the 19th-century writings of Thompson (1851), Darwin (1874), Lindsay (1879), Buchner (1880), and Romanes (1892). For these writers a definition seemed almost unnecessary: play was behavior that was not serious (in the sense of being directed to ac­ complishing some immediate task), was often highly energetic and most characteristic of healthy individuals, and was probably pleasur­ able. But then as now, play was an oddly dis­ continuous category: prominent in some spe­ cies (especially mammals) and absent or rare in most (especially invertebrates and poikilothermic vertebrates). Thus play was, and still is, rarely incorporated into any general system of comparative psychology.