变革型领导研究综述

变革型领导作为近二十多年来领导力研究的热点,在领导力的研究中占有重要的地位。本文对变革型领导的的概念和变革型领导的结构及测量进行了介绍,并对变革型领导有效性和作用机制进行评述,最后对变革型领导研究提出了展望。     

Establishing books as conditioned reinforcers for preschool children as a function of an observational intervention

We tested the effects of an observational intervention (Greer & Singer-Dudek, 2008) on establishing children's books as conditioned reinforcers using a delayed multiple baseline design. Three preschool students with mild language and developmental delays served as the participants. Prior to the intervention, books did not function as reinforcers for any of the participants. The observational intervention consisted of a situation in which the participant observed a confederate being presented with access to books contingent on correct responses and the participant received nothing for correct responses. After several sessions of this treatment, the previously neutral books acquired reinforcing properties for maintenance and acquisition responses for all three participants.     

Effects of a history of differential reinforcement on preference for choice

The effects of a history of differential reinforcement for selecting a free-choice versus a restricted-choice stimulus arrangement on the subsequent responding of 7 undergraduates in a computer-based game of chance were examined using a concurrent-chains arrangement and a multiple-baseline-across-participants design. In the free-choice arrangement, participants selected three numbers, in any order, from an array of eight numbers presented on the computer screen. In the restricted-choice arrangement, participants selected the order of three numbers preselected from the array of eight by a computer program. In initial sessions, all participants demonstrated no consistent preference or preference for restricted choice. Differential reinforcement of free-choice selections resulted in increased preference for free choice immediately and in subsequent sessions in the absence of programmed differential outcomes. For 5 participants, changes in preference for choice were both robust and lasting, suggesting that a history of differential reinforcement for choice may affect preference for choice.     

Sub-Optimal Choice by Pigeons: Failure to Support The Allais Paradox

Pigeons show a preference for an alternative that provides them with discriminative stimuli (sometimes a stimulus that predicts reinforcement and at other times a stimulus that predicts the absence of reinforcement) over an alternative that provides them with nondiscriminative stimuli, even if the nondiscriminative stimulus alternative is associated with 2.5 times as much reinforcement (Stagner & Zentall, 2010). In Experiment 1 we found that the delay to reinforcement associated with the nondiscriminative stimuli could be reduced by almost one half before the pigeons were indifferent between the two alternatives. In Experiment 2 we tested the hypothesis that the preference for the discriminative stimulus alternative resulted from the fact that, like humans, the pigeons were attracted by the stimulus that consistently predicted reinforcement (the Allais paradox). When the probability of reinforcement associated with the discriminative stimulus that predicted reinforcement was reduced from 100% to 80% the pigeons still showed a strong preference for the discriminative stimulus alternative. Thus, under these conditions, the Allais paradox cannot account for the sub-optimal choice behavior shown by pigeons. Instead we propose that sub-optimal choice results from positive contrast between the low expectation of reinforcement associated with the discriminative stimulus alternative and the much higher obtained reinforcement when the stimulus associated with reinforcement appears. We propose that similar processes can account for sub-optimal gambling behavior by humans.     

My life is a longing: Child abuse and its adult sequelae Results of the Brody longitudinal study from birth to age 30

The psychoanalytically oriented Brody longitudinal study has followed the psychological development of 76 individuals from birth to age 30. Ten suffered severe maltreatment in childhood in the form of rejection and/or physical abuse at the hands of one or both parents. This report describes the effects of child abuse on the emerging personalities of the children, as well as on their adult personalities and mental health. Specifi cally, as adults the maltreated children had signifi cantly more psychiatric illness (typically depressions and anxiety disorders), less mature psychological defense mechanisms, more insecure mental representations of attachment to their parents as indicated by the adult attachment interview, and a lower Global Assessment of Functioning than their well-treated counterparts. Additionally, their prevailing moods were joyless. Case examples show the emergence of symptoms, personality disorders, and defenses over time, as well as the workings of ameliorating infl uences. Several of the maltreated children made relatively successful adaptations as adults, indicating children's potential for resilience. Resilience, however, may be a superfi cial concept, for, in this series of cases, seemingly adequate coping in formerly mistreated children always came at the price of emotional vulnerability and compromised potential.     

The influence of robotic guidance on error detection and correction mechanisms

New technologies have expanded the available methods to help individuals learn or re-learn motor skills. Despite equivocal evidence for the impact of robotic guidance for motor skill acquisition (Marchal-Crespo, McHughen, Cramer, & Reinkensmeyer, 2010), we have recently shown that robotic guidance mixed with unassisted practice can significantly improve the learning of a golf putting task (Bested & Tremblay, 2018). To understand the mechanisms associated with this new mixed approach (i.e., unassisted and robot-guided practice) for the learning of a golf putting task, the current study aimed to determine if such mixed practice extends to one’s ability to detect errors. Participants completed a pre-test, an acquisition phase, as well as immediate, delayed (24-h), and transfer post-tests. During the pre-test, kinematic data from the putter was converted into highly accurate, consistent, and smooth trajectories delivered by a robot arm. During acquisition, 2 groups performed putts towards 3 different targets with robotic guidance on either 0% or 50% of acquisition trials. Only the 50% guidance group significantly reduced ball endpoint distance and variability, as well as ball endpoint error estimations, between the pre-test and the post-tests (i.e., immediate retention, 24-h retention, and 24-h transfer). The current study showed that allowing one to experience both robotic guidance and unassisted (i.e., errorful) performances enhances one’s ability to detect errors, which can explain the beneficial motor learning effects of a mixed practice schedule.     

人际信任与合作的培养:基于信任和公共品博弈的实验研究

研究运用经济行为学的博弈实验法,探索了不同人际信任和合作的培养模式的效果问题。实验一和实验二分别采用两人信任博弈和六人公共品博弈实验范式,探讨了替代强化、直接强化和对照组等不同培养模式下的信任和合作关系变化情况。研究结果显示:1、直接强化组的培养效果好于替代强化组; 2、从实验范式角度而言,两人信任博弈范式下的培养效果优于六人公共品博弈范式; 3、相比于直接强化组而言,替代强化组的培养效果不受实验范式和实验情境的影响,具有跨实验情境的一致性和稳定性。因此,在人际信任和合作关系的培养过程中,相比于直接强化模式更容易受时空的限制和实验效应的影响,观察学习等替代强化的模式更具有可行性及推广性。     

Establishing praise as a conditioned reinforcer: Pairing with one versus multiple reinforcers

Praise and other forms of attention may not function as reinforcers for the behavior of children with autism. Previous research demonstrated that contingently pairing praise with reinforcers (response stimulus) can establish praise as a conditioned reinforcer. We evaluated a procedure for establishing praise as a generalized conditioned reinforcer (pair praise with four reinforcers) and compared it with a procedure to establish praise as a conditioned reinforcer (pair praise with one reinforcer). We compared the two conditions in a reversal design with “praise” and “no programmed consequence” conditions rapidly alternated after pairing phases. With three out of five participants with autism, responding in the “pair‐with‐four” condition showed higher levels of responding or more increasing trends compared with that in “pair‐with‐one” condition. We also replicated previous contingent pairing research with two participants in a multiple baseline across participants design. A limitation was the absence of manipulating motivating operations in assessing the efficacy of praise as a generalized conditioned reinforcer. Nevertheless, these data contribute to the research on establishing praise as a reinforcer, and we recommend directions for future research.     

Exchange schedules in token economies: A preliminary investigation of second‐order schedule effects

Basic research shows that token‐production and exchange‐production schedules in token economies affect each other as second‐order schedules (i.e., the exchange‐production schedule's requirements affect responding toward the token‐production schedule). This relationship has not been investigated with children in academic settings despite the widespread use of token economies in this context. This study compared the effects of fixed‐ratio (FR) and variable‐ratio (VR) exchange‐production schedules of equal ratios (2, 5, and 10) on responding toward an FR 1 token‐production schedule with a child diagnosed with autism. A concurrent chains assessment was also conducted to assess the participant's relative preference for FR and VR exchange‐production schedule arrangements within her typical discrete trial training. Results showed no difference in response rate between the two schedule types. However, the concurrent chains assessment revealed an exclusive preference for the VR arrangement.     

Trauma awareness and preparedness: Their influence on posttraumatic stress disorder development related to armed conflict experience

This study examined influences of trauma awareness and preparedness on the development of posttraumatic stress disorder (PTSD) in civilian and military personnel with exposure to the civil war. Participants were 302 people with exposure to civil war in the Democratic Republic of Congo (civilians = 68%; females = 47%; age range = 16 to 76 years old, SD = 13.58 years). Participants completed the Posttraumatic Checklist Scale, General Self-Efficacy Scale, and Traumatic Events List. The data were analysed to predict PTSD development from trauma awareness and preparedness, taking exposure to multiple traumas into account as a risk factor. Findings suggest that trauma awareness and preparedness play an important role among military personnel in moderating the risk of developing PTSD, more so than among the civilian population. Mental health professionals working with civil war survivors should seek to explore trauma awareness and preparedness as resources for minimising risk for PTSD in armed conflict situations.