Baby X

The present study investigated adult behavior while interacting with a three-month-old infant under conditions in which the child was introduced as a boy, as a girl, or with no gender information given. Gender labels did not elicit simple effects, but rather interacted significantly with the sex of the subject on both toy usage and physical contact measures. There was a stronger tendency for both male and female adults to utilize sex-stereotyped toys when the child was introduced as a girl. Most of the findings, however, reflected a differential response of men and women to the absence of gender information. In this condition, male subjects employed a neutral toy most frequently and handled the child least; in contrast, females used more stereotyped toys and handled the child more. All subjects attempted to guess the gender of the child (with “boy” guesses more frequent, although the child was actually female) and all justified their guess on the basis of stereotyped behavioral or physical cues like strength or softness.     

Infantile stimulation and its effects on frustration- and fear-motivated behavior in rats

Infant rats that were either removed from the nest each day (handled) or left undisturbed (nonhandled) were, in adulthood, given 72 food-reinforced runway acquisition trials followed by 24 trials of extinction training with or without shock. Handled and nonhandled control animals were given runway training without food reinforcement. Reinforced rats ran faster than nonreinforced rats, and handled rats ran faster than nonhandled rats during the initial trials of runway acquisition irrespective of the reinforcement condition. Nonhadled rats stopped running sooner than handled rats when shock was introduced in the goalbox, but differences between handled and nonhandled rats given extinction training without shock were small. Results of a second experiment showed no differences between handled and non-handled rats in the magnitude of the depression effect after an incentive shift. It was concluded that infantile handling had little effect on frustration-motivated behavior, but did affect fear-motivated behavior.