PARENTAL BEHAVIOR 



1333 



feet, appearin<2; annoyed when it clings to 

 the mother's body, etc. In contrast, an ex- 

 perienced chimpanzee mother shows a high 

 degree of assurance, directness, and skill in 

 accepting, placing, grooming, cuddling, and 

 in general caring for the young. As Yerkes 

 and Tomilin (1935) say, "the contrast is 

 that of bewilderment and relative uncer- 

 tainty versus familiarity." Similar differ- 

 ences between primiparous and multiparous 

 mothers can be seen in the rhesus monkey 

 (Tinklepaugh and Hartman, 1930), in 

 which primiparous animals seem frightened, 

 excited, and disorganized in the presence of 

 the neonate, compared with multiparous 

 mothers. However, Yerkes (1915) noted 

 that a primiparous rhesus monkey which 

 bore a still birth kept the dead young animal 

 and carried it about the cage for a long pe- 

 i^od. 



Observations in zoos (Hediger, 1955) in- 

 dicate a similar improvement in maternal 

 care in experienced as compared with inex- 

 perienced mothers, in many other animals. 

 Hediger says, "a considerable difference . . . 

 may often be seen between the behavior of 

 experienced mothers and those with their 

 first-born young. This distinction is often 

 indeed, so sharp that the first birth might 

 be considered as something like a dress re- 

 hearsal, not counting for the propagation of 

 the species, but a preparation for subsequent 

 births." 



Ross, Denenberg, Sawin and Meyer 

 (1956) rated the quality of nest-construc- 

 tion of 84 rabbits of various strains, each 

 of which reared four litters of young. They 

 found that the quality of the nest, as rated 

 by various observers, improved linearly up 

 to the third litter. (Deutsch, 1957, felt jus- 

 tified in objecting to this conclusion on the 

 basis of his own observations of two female 

 rabbits w^hich were primiparous at the be- 

 ginning of his observations, and a third 

 which had had an unstated number of pre- 

 vious litters, and which w^ere able to con- 

 struct "fairly uniform nests perfectly, even 

 without any previous experience of dig- 

 ging.") On the other hand, a "maternal pro- 

 tection" score, based on ratings of the in- 

 tensity of the mothers' resistance to the 

 observer's attempts to manipulate the 

 young, did not change from litter to litter 



(Denenberg, Sawin, Frommer and Ross, 

 1958). 



Data on the differences between experi- 

 enced and inexperienced laboratory rats, 

 mice, and guinea pigs are rather contradic- 

 tory. Primaparous animals seem to care for 

 and retrieve the young perfectly adequately, 

 with a full range of appropriate behavior 

 patterns (Avery, 1925; Wiesner and Sheard, 

 1933; Lashley, 1938; Beach and Jaynes, 

 1956a). Some investigators nevertheless re- 

 port differences between primiparous and 

 multiparous animals. Leblond (1940) tested 

 lactating mice by presenting them with 

 young of various ages. In both mice and rats, 

 younger pups are much stronger stimuli for 

 the retrieving response than are older pups 

 (Wiesner and Sheard, 1933). Leblond found 

 that the average age of the young which his 

 lactating mice would retrieve was greater in 

 multiparous than in primiparous animals. 

 He interpreted this as meaning that the 

 multiparous animals could retrieve in re- 

 sponse to somewhat weaker stimulation 

 than that required by the primiparous sub- 

 jects. Frank (1952) reported that primip- 

 arous common voles retrieved less readily 

 and intensely than did multipara. 



Beniest-Noirot (1958), studying domestic 

 mice, found no difference in retrieving (or 

 other aspects of maternal behavior) among 

 groups of primiparous females, virgin fe- 

 males, pregnant females, and males, but her 

 data are based on the presence or absence of 

 the behavior in various individuals, and do 

 not include any measure of frequency or 

 intensity. Similarly, Rowell (1960c) found 

 no differences in the proportions of various 

 kinds of responses given to young by pri- 

 miparous and by multiparous female golden 

 hamsters. Beach and Jaynes (1956a) made 

 a very careful and quantitative comparison 

 of maternal behavior in primiparous and 

 multiparous rats. They graded the rats on 

 the number of pups poorly cleaned, num- 

 ber of pups found outside the nest, quality 

 of the nest, etc. They also tested them for 

 retrieving behavior by a method which 

 yielded data on both the latency and the 

 frequency of retrieving during a test period. 

 They found no difference with respect to 

 any of these measures between primiparous 

 and multiparous animals. The multiparous 

 rats of Beach and Jaynes' experiment had 



