Summary: A large behavioral and EEG study reports that men who score high on social dominance make faster decisions across a range of tasks, and this promptness is linked to a distinct brain signal.
Source: EPFL.
Study Overview
Social hierarchies are a common feature of human and animal groups, and dominance helps determine priority access to resources and influence within those hierarchies. Researchers have long observed that acting quickly in social situations can help an individual become or remain dominant, but whether dominant people also make faster decisions outside of social competition was unclear.
To address this question, researchers from the labs of Carmen Sandi and Michael Herzog at EPFL conducted a large behavioral study focused on male participants. The team tested 240 male students from EPFL and the University of Lausanne (UNIL). Participants completed a validated dominance questionnaire that grouped them into high- and low-dominance categories. Decision-making speed and accuracy were then examined across several tasks that did not require social competition.
Tasks and Behavioral Results
The study included five tasks designed to measure different aspects of cognitive performance. Participants completed emotion discrimination, memory and recognition, route learning, and a simple reaction-time control task. Specifically:
- Emotion discrimination: identifying emotions from facial expressions;
- Face memory and recognition: remembering and later recognizing faces;
- Route learning: learning and recalling a route;
- Simple reaction task: pressing the spacebar as soon as a grey square appeared on the screen (control task).
Across the choice-based tasks (emotion discrimination, memory/recognition, and route learning), men who scored high in social dominance consistently responded faster than low-dominance men without sacrificing accuracy. In the simple reaction control task, however, both groups performed similarly, indicating that the faster responses from high-dominance men were not due to general motor speed but linked to decision-making under choice conditions.
EEG Findings and Neural Signatures
To explore neural mechanisms underlying faster decision-making, the researchers recorded high-density electroencephalography (EEG) while participants completed face-emotion discrimination tasks. EEG allowed the team to examine the timing and strength of brain activity tied to the decision process.
The EEG analysis revealed a pronounced increase in an event-related brain signal approximately 240 milliseconds after stimulus onset in high-dominance men compared with low-dominance men. Source imaging localized greater activity in several regions associated with emotion processing and action selection, including the left insula and cingulate cortex, as well as the right inferior temporal and right angular gyri.
These neural differences suggest that dominant individuals recruit emotion- and behavior-related brain networks more strongly or more rapidly during decision-making, providing a plausible biological basis for their faster responses in choice situations.
Implications and Future Directions
The findings indicate that promptness to respond in choice situations—independent of social context—could serve as a behavioral and neural marker of social dominance. Because the faster responding was observed without a loss of accuracy, promptness appears to be a stable feature of how dominant men process and act on information rather than a speed–accuracy trade-off.
Lead researcher Carmen Sandi noted the potential for further studies to expand on these results: for example, whether similar EEG signatures appear in highly dominant individuals in real-world leadership roles, whether comparable patterns exist in women, and whether these differences are present in children. If replicated, EEG markers may become a noninvasive tool to study social disposition and its development.
Funding: Swiss National Science Foundation (NCCR Synapsy), Oak Foundation, EU FP7 (MATRICS), EPFL, and FCT Portugal supported this research.
Source and Publisher: Nik Papageorgiou, EPFL. Organized and reported by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image in the public domain.
Original research: Open-access study titled “Dominant men are faster in decision-making situations and exhibit a distinct neural signal for promptness,” authored by Janir da Cruz, João Rodrigues, John C. Thoresen, Vitaly Chicherov, Patrícia Figueiredo, Michael H. Herzog, and Carmen Sandi, published in Cerebral Cortex on August 15, 2018. doi: 10.1093/cercor/bhy195
Abstract (condensed)
Social dominance contributes to hierarchical organization by enabling priority access to resources. Acting quickly in social contexts favors the emergence of dominance, but whether dominance correlates with generalized fast decision-making was uncertain. After classifying participants by social dominance motivation, the study found that men high in dominance responded faster, without loss of accuracy, across multiple decision-making tasks but not in a simple reaction task. EEG data linked promptness in choice tasks to an amplified neural signal around 240 ms post-stimulus, with greater activation in brain regions related to emotion and behavior. These results suggest that rapid responding in choice situations is a potential biomarker of social disposition.