Longitudinal Associations among Parental Acceptance,Familism Values,and Sibling Intimacy in Mexican‐Origin Families

Prospective associations among parent – adolescent acceptance and familism values in early and middle adolescence and sibling intimacy in late adolescence and young adulthood were assessed in 246 Mexican‐origin families. Older sibling gender and sibling gender constellation were investigated as moderators of these associations. Sibling intimacy was stable over time and younger siblings with older sisters reported higher levels of sibling intimacy than those with older brothers. As predicted, stronger familism values were associated with greater sibling intimacy, but this link was evident only for older sisters and for girl‐girl dyads. The links from mother‐ and father‐acceptance to sibling intimacy also depended on the gender constellation of the sibling dyad: Higher levels of maternal warmth were associated with greater sibling intimacy for older sisters and girl‐girl sibling pairs but higher levels of paternal warmth were linked to greater sibling intimacy only for older siblings in mixed‐gender sibling dyads. Findings are consistent with prior research on the role of gender in family relationships but extend this work to encompass the effects of both parents' and siblings' gender, as well as the role of sociocultural values in parents' socialization influences.     

Self-ambivalence and resistance to subtle self-change attempts

Recent research has demonstrated the malleability of self-views to subtle situational influence but has not uncovered features of the self-concept representation that make it susceptible to such change. Using research on attitude ambivalence as a foundation, the current article predicted that the self would be most likely to respond to a subtle change induction when the targeted self-beliefs were objectively ambivalent (e.g., possessed both positive and negative features). Using self-esteem conditioning (Experiment 1) and outgroup stereotype priming (Experiment 2), it was found that people were more susceptible to subtle change inductions as objective self-ambivalence increased. Notably, the consistency between dominant self-views (positive or negative) and the change induction did not influence these results. These effects held for objective ambivalence, but not subjective ambivalence, and only when the objective ambivalence measure was relevant to the change induction. Mechanisms of the observed moderation and the implications of self-ambivalence for understanding self-change are discussed.     

Roles of nucleus accumbens and basolateral amygdala in autoshaped lever pressing

Initially-neutral cues paired with rewards are thought to acquire motivational significance, as if the incentive motivational value of the reward is transferred to the cue. Such cues may serve as secondary reinforcers to establish new learning, modulate the performance of instrumental action (Pavlovian-instrumental transfer, PIT), and be the targets of approach and other cue-directed behaviors. Here we examined the effects of lesions of the ventral striatal nucleus accumbens (ACb) and the basolateral amygdala (BLA) on the acquisition of discriminative autoshaped lever-pressing in rats. Insertion of one lever into the experimental chamber was reinforced by sucrose delivery, but insertion of another lever was not reinforced. Although sucrose was delivered independently of the rats' behavior, sham-lesioned rats rapidly came to press the reinforced but not the nonreinforced lever. Bilateral ACb lesions impaired the initial acquisition of sign-tracking but not its terminal levels. In contrast, BLA lesions produced substantial deficits in terminal levels of sign-tracking. Furthermore, whereas ACb lesions primarily affected the probability of lever press responses, BLA lesions mostly affected the rate of responding once it occurred. Finally, disconnection lesions that disrupted communication between ACb and BLA produced both sets of deficits. We suggest that ACb is important for initial acquisition of consummatory-like responses that incorporate hedonic aspects of the reward, while BLA serves to enhance such incentive salience once it is acquired.