No abstract

9 litters of BALB/c mice were divided into 3 groups: (a) a maternal separation group placed in an incubator during separation, (b) a non-incubated separation group, and (c) a non-separated control group. Beginning 24 hr. after birth, the mothers of the separation groups were removed from their pups for 20 hr. per day for 18 consecutive days. At 50 days of age, all Ss were tested in an automated open field on 3 dependent measures, activity level, quadrants traversed, and defecation. The results were inconsistent with those of previous studies. It was concluded that no effect of maternal separation on adult patterns of emotional reactivity was demonstrated.

The effects of differentially preferred extrinsic rewards and familiarity of rewarder on subsequent intrinsic motivation for a reading task were investigated in 96 second-, third-, and fourth-grade children. The results revealed that children rewarded by a controlling familiar person spent less time with a book and read fewer words than those rewarded by an unfamiliar person, except when no reward was offered. For the controlling familiar groups, the high-preference reward condition resulted in significantly less time spent with the book than did the no-reward condition. For the unfamiliar groups, in contrast, the high-preference condition resulted in significantly more time spent with the book than did the no-reward condition. These findings are discussed within the context of cognitive evaluation theory. 313