Addressing climate change with behavioral science: A global intervention tournament in 63 countries.

Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions' effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior-several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people's initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors.

Individual-level solutions may support system-level change â if they are internalized as part of one's social identity.

System-level change is crucial for solving society's most pressing problems. However, individual-level interventions may be useful for creating behavioral change before system-level change is in place and for increasing necessary public support for system-level solutions. Participating in individual-level solutions may increase support for system-level solutions - especially if the individual-level solutions are internalized as part of one's social identity.

Interindividual differences in environmentally relevant positive trait affect impacts sustainable behavior in everyday life.

Emotions are powerful drivers of human behavior that may make people aware of the urgency to act to mitigate climate change and provide a motivational basis to engage in sustainable action. However, attempts to leverage emotions via climate communications have yielded unsatisfactory results, with many interventions failing to produce the desired behaviors. It is important to understand the underlying affective mechanisms when designing communications, rather than treating emotions as simple behavioral levers that directly impact behavior. Across two field experiments, we show that individual predispositions to experience positive emotions in an environmental context (trait affect) predict pro-environmental actions and corresponding shifts in affective states (towards personal as well as witnessed pro-environmental actions). Moreover, trait affect predicts the individual behavioral impact of positively valenced emotion-based intervention strategies from environmental messages. These findings have important implications for the targeted design of affect-based interventions aiming to promote sustainable behavior and may be of interest within other domains that utilize similar intervention strategies (e.g., within the health domain).

Atypical processing of social anticipation and feedback in borderline personality disorder.

BACKGROUND-: Borderline personality disorder (BPD) is characterized by maladaptive social functioning, and widespread negativity biases. The neural underpinnings of these impairments remain elusive. We thus tested whether BPD patients show atypical neural activity when processing social (compared to non-social) anticipation, feedback, and particularly, how they relate to each other. METHODS-: We acquired functional MRI data from 21 BPD women and 24 matched healthy controls (HCs) while they performed a task in which cues and feedbacks were either social (neutral faces for cues; happy or angry faces for positive and negative feedbacks, respectively) or non-social (dollar sign; winning or losing money for positive and negative feedbacks, respectively). This task allowed for the analysis of social anticipatory cues, performance-based feedback, and their interaction. RESULTS-: Compared to HCs, BPD patients expressed increased activation in the superior temporal sulcus during the processing of social cues, consistent with elevated salience associated with an upcoming social event. BPD patients also showed reduced activation in the amygdala while processing evaluative social feedback. Importantly, perigenual anterior cingulate cortex (pgACC) activity during the presentation of the social cue correlated with reduced amygdala activity during the presentation of the negative social feedback in the BPD patients. CONCLUSIONS-: These neuroimaging results clarify how BPD patients express altered responses to different types of social stimuli (i.e. social anticipatory cues and evaluative feedback) and uncover an atypical relationship between frontolimbic regions (pgACC-amygdala) over the time span of a social interaction. These findings may help to explain why BPD patients suffer from pervasive difficulties adapting their behavior in the context of interpersonal relationships and should be considered while designing better-targeted interventions.

Physical pain recruits the nucleus accumbens during social distress in borderline personality disorder.

Patients with borderline personality disorder (BPD) often engage in dangerous self-injurious behaviors (SIBs) as a maladaptive technique to decrease heightened feelings of distress (e.g. negative feelings caused by social exclusion). The reward system has recently been proposed as a plausible neural substrate, which may influence the interaction between social distress and physical pain processing in patients that engage in SIBs. Using functional magnetic resonance imaging (fMRI) in 20 adult BPD patients with a history of SIBs and 23 healthy controls (HCs), we found a hyper-activation of the nucleus accumbens (NAcc) and amygdala when painful stimuli were presented to BPD patients (but not HCs) in a state of heightened distress, induced via social exclusion. This differential NAcc activity was mediated by anxious attachment style, which is a key developmental feature of the disorder. Altogether, these results suggest a neural mechanism underlying the pathophysiology of SIBs in these patients, which is likely reinforced via the reward system.

Correction: Linking Individual Learning Styles to Approach-Avoidance Motivational Traits and Computational Aspects of Reinforcement Learning.

[This corrects the article DOI: 10.1371/journal.pone.0166675.].

The "Creative Right Brain" Revisited: Individual Creativity and Associative Priming in the Right Hemisphere Relate to Hemispheric Asymmetries in Reward Brain Function.

The idea that creativity resides in the right cerebral hemisphere is persistent in popular science, but has been widely frowned upon by the scientific community due to little empirical support. Yet, creativity is believed to rely on the ability to combine remote concepts into novel and useful ideas, an ability which would depend on associative processing in the right hemisphere. Moreover, associative processing is modulated by dopamine, and asymmetries in dopamine functionality between hemispheres may imbalance the expression of their implemented cognitive functions. Here, by uniting these largely disconnected concepts, we hypothesize that relatively less dopamine function in the right hemisphere boosts creativity by releasing constraining effects of dopamine on remote associations. Indeed, participants with reduced neural responses in the dopaminergic system of the right hemisphere (estimated by functional MRI in a reward task with positive and negative feedback), displayed higher creativity (estimated by convergent and divergent tasks), and increased associative processing in the right hemisphere (estimated by a lateralized lexical decision task). Our findings offer unprecedented empirical support for a crucial and specific contribution of the right hemisphere to creativity. More importantly our study provides a comprehensive view on potential determinants of human creativity, namely dopamine-related activity and associative processing.

Linking Individual Learning Styles to Approach-Avoidance Motivational Traits and Computational Aspects of Reinforcement Learning.

Learning how to gain rewards (approach learning) and avoid punishments (avoidance learning) is fundamental for everyday life. While individual differences in approach and avoidance learning styles have been related to genetics and aging, the contribution of personality factors, such as traits, remains undetermined. Moreover, little is known about the computational mechanisms mediating differences in learning styles. Here, we used a probabilistic selection task with positive and negative feedbacks, in combination with computational modelling, to show that individuals displaying better approach (vs. avoidance) learning scored higher on measures of approach (vs. avoidance) trait motivation, but, paradoxically, also displayed reduced learning speed following positive (vs. negative) outcomes. These data suggest that learning different types of information depend on associated reward values and internal motivational drives, possibly determined by personality traits.

Hemispheric Asymmetries in Striatal Reward Responses Relate to Approach-Avoidance Learning and Encoding of Positive-Negative Prediction Errors in Dopaminergic Midbrain Regions.

Some individuals are better at learning about rewarding situations, whereas others are inclined to avoid punishments (i.e., enhanced approach or avoidance learning, respectively). In reinforcement learning, action values are increased when outcomes are better than predicted (positive prediction errors [PEs]) and decreased for worse than predicted outcomes (negative PEs). Because actions with high and low values are approached and avoided, respectively, individual differences in the neural encoding of PEs may influence the balance between approach-avoidance learning. Recent correlational approaches also indicate that biases in approach-avoidance learning involve hemispheric asymmetries in dopamine function. However, the computational and neural mechanisms underpinning such learning biases remain unknown. Here we assessed hemispheric reward asymmetry in striatal activity in 34 human participants who performed a task involving rewards and punishments. We show that the relative difference in reward response between hemispheres relates to individual biases in approach-avoidance learning. Moreover, using a computational modeling approach, we demonstrate that better encoding of positive (vs negative) PEs in dopaminergic midbrain regions is associated with better approach (vs avoidance) learning, specifically in participants with larger reward responses in the left (vs right) ventral striatum. Thus, individual dispositions or traits may be determined by neural processes acting to constrain learning about specific aspects of the world.