A double-edged sword: How social diversity affects trust in representatives via perceived competence and warmth

Previous research has claimed that diversity erodes trust, even though the empirical evidence is mixed and restricted to ethnic neighborhood diversity. Against the backdrop of increasing diversity within the political sphere and concurrently declining political trust, we examined the impact of social diversity on trust in groups of political representatives. In two experiments (N₁ = 109, N₂ = 248) we tested how the diversity of political parties affected citizens’ trust in them. In line with predictions of the stereotype content model, diverse parties were perceived as warmer and less competent than non-diverse parties (Experiments 1–2). Additionally, party diversity was perceived as having more benefits, but also involving more threats (Experiment 2). Consequently, diversity had both positive (via warmth and benefits) and negative (via competence and threats) indirect effects on trust. These results help to untangle previously mixed, for the most part non-experimental, findings of the relationship between diversity and trust.     

Developmental kinesics: How children acquire communicative and non-communicative nonverbal behavior

This article is a position paper concerning the major issues in the study of children's acquistion of nonverbal behavior. In linguistic theory non-verbal behavior may be considered irrelevant, it may be condsidered the precursor of verbal language, or it may be viewed as an integral part of human communication which is verbal and nonverbal. The author opts for the latter theory. Concerning the relationship between what is innate and what is learned, the paper discusses that nonverbal expression is innate, but culture determines its forms and its uses. The paper then presents a brief history of Developmental Kinesics, explaining its technical difficulties and its methodological complexities. It proceeds by documenting the function of maternal nonverbal behavior towards the neonate. Finally, the paper treats the levels of analysis. A distinction is drawn between communicative and non-communicative nonverbal behavior. Its affective, emotional function relates to ego state; its regulatory function governs face-to-face interaction; and its referential, informative function pertains to the message proper. The child also acquires the non-interactional aspects of body movements which distinguish different peoples. Expression and perception must be studied separately; and finally, nonverbal behavior has to be correlated with verbal behavior and particular attention has to be focused on the double bind.     

Stress for families today

Rapid changes in family life have created enormous challenges and pressures on developing families - divorce, two working parents, disappearance of the extended family, unclear cultural values for our children's future, poorly defined support systems for stressed families, inadequate substitute care when both parents work-all contribute to an anxious atmosphere for young families. Parents who must return to work „too early”︁ (and we have no established standards yet for what this means to either child or adult development) seem to grieve about the loss of the relationship with the developing child. They may even set up defenses against making a strong and painful attachment. They may not become involved in the child's development in a way that will foster their own development as nurturing adults. The grieving and the necessary defenses against it are predictable and must be mitigated in order to foster nurturing adults within the family. Children must be provided with caring, intensely involved adults in order to assure their optimal future development. We must provide them and their parents with adequate substitute care. This paper suggests adjustments at the industrial level that must be made to foster parental involvement and to assure positive outcomes for future generations.     

Identification of a reinforcement pathway necessary for operant conditioning of head waving in Aplysia californica

The marine mollusc Aplysia californica exhibits a wide range of nonassociative and associative forms of learning. Recently, we found that the learning repertoire of Aplysia includes operant conditioning (Cook & Carew, 1986, 1989b). The behavior we examined is a naturally occurring, side-to-side head-waving response used by Aplysia in seeking food, obtaining a foothold, and egg laying. Aplysia can be operantly conditioned to reduce head-waving to one side of their body if such a response results in exposure to bright uniform-field illumination, which the animals find aversive. An essential step toward achieving a mechanistic understanding of operant conditioning is to identify and characterize the reinforcement pathway used during the learning. Toward this end, we wished to determine which of the peripheral visual pathways in Aplysia are critical for performance of the operant task. Previous experiments indicated that photic input from the optic and rhinophore nerves functionally inhibited motor neurons that participate in the operant response (head-waving), while photic input from the oral veil nerves excited these same motor neurons (Cook & Carew, 1989c). These findings suggested the hypothesis that one or both of these pathways could play an important role in mediating reinforcement during training. To explore this possibility we operantly trained animals that had received chronic bilateral transections of either the optic and rhinophore nerves or the oral veil nerves C1-C3 (in conjunction with transection of the optic and rhinophore nerves). We found that operant conditioning was not disrupted by ablation of input from the eyes and rhinophores. By contrast, ablation of input from the oral veil (together with that from the eyes and rhinophores) abolished operant conditioning. Thus, the oral veil nerves play a critical modulatory role in operant conditioning of head-waving. This observation further suggested that photic input from the oral veil is conveyed to the CNS via the oral veil nerves. In a final experiment we confirmed that stimulation of the oral veil with light evokes increased afferent activity in the oral veil nerves C1-C2. These results support the idea that the oral veil nerves contain processes that are critical components of the reinforcement pathway for operant conditioning of head-waving.     

REM sleep deprivation increases early morning pineal melatonin in castrated rats

Recently nighttime melatonin levels have been shown to be attenuated in depressive patients or patients with dementia of the Alzheimer type. On the other hand, depression can be transiently relieved by deprivation of rapid eye movement sleep. Since exogenous melatonin administration increases rapid eye movement sleep and slow wave sleep in the rat, could rapid eye movement sleep deprivation then inversely influence endogenous melatonin production? We found indices that in castrated Wistar rats 4 days of rapid eye movement sleep deprivation by the cuff pedestal method elevates the pineal content of melatonin by a factor of two at 1 to 2 h after light onset. Rapid eye movement sleep is thus suggested to influence pineal activity. This mechanism might be involved in the human depression-alleviating effect of rapid eye movement sleep deprivation.     

Delayed-onset sensitization emerges after dishabituation in developing Aplysia.

A recent study of the development of nonassociative learning in the siphon withdrawal reflex of Aplysia showed that dishabituation (facilitation of an habituated response) and sensitization (facilitation of a nonhabituated response) emerge according to different developmental timetables: dishabituation precedes sensitization by approximately 60 days (Rankin & Carew, 1988). Both forms of facilitation of the reflex were observed within 90 s of an electrical shock to the tail. However, more recent work by Marcus and colleagues (1988) in adult animals revealed that sensitization can have a delayed onset of 20-30 min after a strong tail shock. Since the developmental study of Rankin and Carew (1988) only tested the reflex for 10 min after tail shock, it is possible that sensitization was in fact present at earlier developmental stages, but was undetected. To examine this question, in the present study we utilized a longer (40-50 min) post-shock observation period to determine whether delayed-onset sensitization is exhibited in juvenile Aplysia, and if so, when it is expressed during development. In our first experiment, we found that Early Stage 12 juveniles (80-95 days after metamorphosis) showed significant delayed-onset sensitization 30-50 min after a strong tail shock. In a second experiment, we found that delayed-onset sensitization was absent in Stage 11 animals (20-70 days after metamorphosis). Thus delayed-onset sensitization emerges in Early Stage 12. The fact that the birthdate of delayed-onset sensitization is at least 30 days after that of dishabituation (Rankin & Carew, 1987, 1988) supports the hypothesis that these two forms of nonassociative learning may have at least partly different underlying mechanisms.     

Intraseptal administration of bicuculline produces working memory impairments in the rat.

Male Sprague-Dawley rats, trained to perform a delayed-non-match-to-sample eight-arm radial maze task, were implanted with a single cannula aimed at the medial septal nucleus. A within-subjects design was utilized to examine the effects of intraseptal administration of bicuculline (0.5 micrograms) on performance of this task with 1- and 4-h delay intervals imposed between choices four and five. Administration of bicuculline immediately following the first four choices produced an impairment in maze performance at both a 1- and a 4-h delay interval. This treatment also produced an increase in latency per choice. Bicuculline-induced impairments were not observed when administered 2 h following the predelay session (2 h prior to testing). These data support previous observations that pharmacological manipulation of GABAergic activity within the septum modifies working memory processes.     

Reversal of retrieval impairment caused by retroactive interference on a two-way active avoidance task in rats

Rats were exposed to an open field with flashing light (OFL; 60-W lamp, 30 Hz, for 7 min) 2 h after training and/or 2 h before testing in a two-way active avoidance task (30 trials, 0.5-mA footshock). Post-training OFL presentation caused retroactive interference, i.e., a retrieval impairment/amnesia for the avoidance task. Pretest OFL exposure reversed the post-training OFL-induced retrieval deficit. Diazepam (2.0 mg/kg), atropine (2.0 mg/kg), and methylatropine (0.1 mg/kg) administered before post-training OFL presentation blocked the OFL amnesic effect. However, these drugs did not counteract the pretest OFL-induced recovery of retrieval. Atropine and methylatropine administered 2 h before testing to rats receiving only post-training OFL presentation canceled the OFL-interfering effect. These results suggest: (1) that the amnesic effect of post-training OFL is due to failure of retrieval of the avoidance task, (2) that the reversal of this retrieval impairment by pretest OFL exposure may involve either priming or state-dependent mechanisms, and (3) that there are different modulatory mechanisms involved in post-training and pretest OFL effects.     

Seeing the World in Pink and Blue: Developing and Exploring a New Measure of Essentialistic Thinking about Gender

Sex Roles - Essentialism, or the belief that certain categories have fundamental, intrinsic, and stable essences, pervasively influences social judgments. Among the many groupings that describe...     

Robots as Malevolent Moral Agents: Harmful Behavior Results in Dehumanization,Not Anthropomorphism

A robot's decision to harm a person is sometimes considered to be the ultimate proof of it gaining a human-like mind. Here, we contrasted predictions about attribution of mental capacities from moral typecasting theory, with the denial of agency from dehumanization literature. Experiments 1 and 2 investigated mind perception for intentionally and accidentally harmful robotic agents based on text and image vignettes. Experiment 3 disambiguated agent intention (malevolent and benevolent), and additionally varied the type of agent (robotic and human) using short computer-generated animations. Harmful robotic agents were consistently imbued with mental states to a lower degree than benevolent agents, supporting the dehumanization account. Further results revealed that a human moral patient appeared to suffer less when depicted with a robotic agent than with another human. The findings suggest that future robots may become subject to human-like dehumanization mechanisms, which challenges the established beliefs about anthropomorphism in the domain of moral interactions.