In-group biases and oculomotor responses: beyond simple approach motivation

Oxytocin promotes species-relevant outgroup attention in bonobos and chimpanzees

Previous research has found that oxytocin (OT) is associated with intergroup behaviour in humans as well as wild chimpanzees, and that exogenous OT affects Pan social attention. The two Pan species, bonobos and chimpanzees, differ drastically from one another in their intensity of intergroup competition, with lethal intergroup aggression often led by males in chimpanzees and more tolerant associations often centered around females in bonobos. However, it remains unclear how exogenous OT changes the two species' responses to ingroup and outgroup individuals. In this study, after intranasal administration of nebulized OT or placebo control, chimpanzees and bonobos viewed image pairs of ingroup and outgroup conspecifics while their eye movements were tracked with an eye-tracker. Although the overall effect of OT was small, we found that OT shifted bonobos' and chimpanzees' attention to outgroup images of the sex primarily involved in intergroup encounters in each species. Specifically, OT selectively shifted attention towards outgroup photos of female conspecifics in bonobos, and those of outgroup male conspecifics in chimpanzees. This suggests that OT generally promotes outgroup attention in both bonobos and chimpanzees but this effect is restricted to the sex most relevant in intergroup relations. These results suggest that, although OT may have a generally conserved role in hominid intergroup behaviour, it may act in species-relevant ways under the influence of their socio-ecological backgrounds.

Self-prioritization with unisensory and multisensory stimuli in a matching task

A shape-label matching task is commonly used to examine the self-advantage in motor reaction-time responses (the Self-Prioritization Effect; SPE). In the present study, auditory labels were introduced, and, for the first time, responses to unisensory auditory, unisensory visual, and multisensory object-label stimuli were compared across block-type (i.e., trials blocked by sensory modality type, and intermixed trials of unisensory and multisensory stimuli). Auditory stimulus intensity was presented at either 50 dB (Group 1) or 70 dB (Group 2). The participants in Group 2 also completed a multisensory detection task, making simple speeded motor responses to the shape and sound stimuli and their multisensory combinations. In the matching task, the SPE was diminished in intermixed trials, and in responses to the unisensory auditory stimuli as compared with the multisensory (visual shape+auditory label) stimuli. In contrast, the SPE did not differ in responses to the unisensory visual and multisensory (auditory object+visual label) stimuli. The matching task was associated with multisensory ‘costs’ rather than gains, but response times to self- versus stranger-associated stimuli were differentially affected by the type of multisensory stimulus (auditory object+visual label or visual shape+auditory label). The SPE was thus modulated both by block-type and the combination of object and label stimulus modalities. There was no SPE in the detection task. Taken together, these findings suggest that the SPE with unisensory and multisensory stimuli is modulated by both stimulus- and task-related parameters within the matching task. The SPE does not transfer to a significant motor speed gain when the self-associations are not task-relevant.

Self-Hierarchy in Perceptual Matching: Variations in Different Processing Stages

People have three cognitive representations of the self, namely, the individual, relational, and collective selves (CS), which are indispensable components of selfhood but not necessarily given equal preference. Previous studies found that people displayed varied self-hierarchy in miscellaneous tasks involving different research materials that had pre-existing learned associations established over long periods of time. Therefore, this study tries to explore a purer self-hierarchy without the influence of research materials, using perceptual matching tasks. The behavioral and event-related potentials' (ERPs) findings showed that people recognized information association with their individual self (IS) faster compared with their relational (RS) and CS. Smaller N2, stronger P3 and late positive complex (LPC) amplitudes were evoked during IS compared with RS and CS. However, the three selves evoked equal P2 amplitudes at the early processing stage. Moreover, CS showed a weaker advantage than RS, demonstrating a longer reaction time, lower d prime, and weaker P3 and LPC amplitudes in the parietal region. Overall, self-hierarchy during simple perceptual processing manifested as IS > RS > CS at the late processing stage but manifested as IS = RS = CS at the early processing stage. Self-hierarchy varies according to the processing stage, even without meaningful information and during the simple perception processing. This result provides direct evidence that all selves can be tagged with neutral actions, which would fit the idea of an organism attuned to self-survival at multiple processing levels.

The Hierarchical Relationship Between the Relational-Self and the Collective-Self During Attention Processing

Background

Under the Chinese collectivist cultural system, people emphasize social connections with close others and members of in-groups. Collectivism can be divided into the following two forms: relational collectivism (privileges relational self [RS]) and group collectivism (emphasizes collective self [CS]). Previous researchers have found a hierarchy between the RS and CS, resulting in different degrees of recognition advantages. However, the hierarchy between the RS and CS is unclear and may depend on the specific processing stage. Therefore, this research compared the hierarchy between these two selves during different processing stages using an eye-movement method.

Methods

The sample consisted of thirty-eight young adults aged between 18 and 24 years old (M = 20.45, SD= 1.62). Each participant finished a dot-probe task featuring high-relevant (HR, ie one’s mother’s name and China) and low-relevant (LR, ie, name of a famous person and USA) information about the RS and CS and neutral information. Further, the eye-movement (EM) indices were collected simultaneously.

Results

A stronger reaction time bias and longer total gaze duration revealed that young people in China focus more on RS information, indicating that Chinese people prioritize the RS over the CS at late stages of attentional processing.

Conclusion

Information on interpersonal relationships and information on the in-group both catch people’s attention quickly and easily, but only RS information can maintain attention for longer. Understanding the hierarchy of the RS and the CS may provide more evidence for self-construal in the Chinese collectivist cultural context. The importance of the RS prompting that the interpersonal and close relationships are more important to the development of the self, suggesting that it is necessary to pay more attention to the impact of interpersonal support on people’s mental health in clinical applications.

Overlap in processing advantages for minimal ingroups and the self

Cognitive biases shape our perception of the world and our interactions with other people. Information related to the self and our social ingroups is prioritised for cognitive processing and can therefore form some of these key biases. However, ingroup biases may be elicited not only for established social groups, but also for minimal groups assigned by novel or random social categorisation. Moreover, whether these ‘ingroup biases’ are related to self-processing is unknown. Across three experiments, we utilised a social associative matching paradigm to examine whether the cognitive mechanisms underpinning the effects of minimal groups overlapped with those that prioritise the self, and whether minimal group allocation causes early processing advantages. We found significant advantages in response time and sensitivity (dprime) for stimuli associated with newly-assigned ingroups. Further, self-biases and ingroup-biases were positively correlated across individuals (Experiments 1 and 3). However, when the task was such that ingroup and self associations competed, only the self-advantage was detected (Experiment 2). These results demonstrate that even random group allocation quickly captures attention and enhances processing. Positive correlations between the self- and ingroup-biases suggest a common cognitive mechanism across individuals. These findings have implications for understanding how social biases filter our perception of the world.

Attentional saliency and ingroup biases: From society to the brain

There is ample evidence demonstrating intergroup biases on cognition and emotion. However, it remains unclear how exactly group identification influences these processes, with issues of context sensitivity and goal dependence remaining open to scrutiny. Providing a range of interdisciplinary material, the current review attempts to inform understanding of these issues. Specifically, we provide evidence revealing that individuals show enhanced attention for stimuli associated with an ingroup compared to an outgroup. At the attentional level, such biases can be explained by the assignment of different levels of saliency to ingroup versus outgroup targets. Critically, however, salience assignment is not fixed but varies as a function of context and goal-directed behavior. We suggest that the network in the brain previously associated with social and emotional saliency and attention - notably the anterior insula, posterior superior temporal sulcus, and dorsolateral prefrontal cortex - underpins these effects. Moreover, although attention typically favors ingroup targets, outgroup members can be prioritized on occasion. The implications of this viewpoint and future lines of investigation are considered.