First impressions are commonly assumed to be particularly important; instead, judgments of the targets in later situations were more strongly associated with overall impressions, indicating an acquaintance effect

There Is No Primacy Effect in Interpersonal Perception: A Series of Preregistered Analyses Using Judgments of Actual Behavior. Anne Wiedenroth, Nele M. Wessels, Daniel Leising. Social Psychological and Personality Science, November 13, 2020. https://doi.org/10.1177/1948550620969279

Rolf Degen's take: https://twitter.com/DegenRolf/status/1327527434909065217

Abstract: First impressions are commonly assumed to be particularly important: Information about a person that we obtain early on may shape our overall impression of that person more strongly than information obtained later. In contrast to previous research, the present series of preregistered analyses uses actual person judgment data to investigate this so-called primacy effect: Perceivers (N = 1,395) judged the videotaped behavior of target persons (N = 200) in 10 different situations. Separate subsamples of about 200 perceivers each were used in moving from exploratory to increasingly confirmatory analyses. Contrary to our expectations, no primacy effect was found. Instead, judgments of the targets in later situations were more strongly associated with overall impressions, indicating an acquaintance effect. Relying on early information seems unreasonable when more comprehensive information is readily available. Early information may, however, affect perceivers’ behavioral reactions to the targets and thus their future interactions, if such interactions are possible.

Keywords: primacy effect, order effects, impression formation, behavior observation, personality judgment

Rolf Degen summarizing... Although dopamine boost the anticipation of rewards in humans, it has little or no effect on felt pleasure during the fulfillment of needs

Using pharmacological manipulations to study the role of dopamine in human reward functioning: A review of studies in healthy adults. Heather E. Webber et al. Neuroscience & Biobehavioral Reviews, November 14 2020. https://doi.org/10.1016/j.neubiorev.2020.11.004

Rolf Degen's take: https://twitter.com/DegenRolf/status/1327628962697252864

Highlights

• The role of dopamine in human reward functioning is highly researched.

• Drug challenge studies are translational and have good experimental control.

• Dopamine drug challenge studies in healthy adults were summarized by reward phase.

• Dopamine drugs have differing effects on various reward phases.

• Drug effects are likely nonlinear and behavioral effects depend on outcome measure.

Abstract: Dopamine (DA) plays a key role in reward processing and is implicated in psychological disorders such as depression, substance use, and schizophrenia. The role of DA in reward processing is an area of highly active research. One approach to this question is drug challenge studies with drugs known to alter DA function. These studies provide good experimental control and can be performed in parallel in laboratory animals and humans. This review aimed to summarize results of studies using pharmacological manipulations of DA in healthy adults. ‘Reward’ is a complex process, so we separated ‘phases’ of reward, including anticipation, evaluation of cost and benefits of upcoming reward, execution of actions to obtain reward, pleasure in response to receiving a reward, and reward learning. Results indicated that i) DAergic drugs have different effects on different phases of reward; ii) the relationship between DA and reward functioning appears unlikely to be linear; iii) our ability to detect the effects of DAergic drugs varies depending on whether subjective, behavioral, imaging measures are used.

Keywords: dopaminereward functioningpharmacological challengeanticipationexecutioninvigorationevaluation of costsmotivationeffortlearningpleasure