Periodic Reporting for period 3 - AWAR (Adapted to War)
Période du rapport: 2024-04-01 au 2025-09-30
Was small-scale war a recurrent feature of life during human evolution and, consequently, have humans evolved adaptations to war? This question has generated major interdisciplinary debate involving anthropologists, archaeologists, economists, historians, primatologists, psychologists, and political scientists. The debate remains unsettled, with some scholars claiming that humans come from a long evolutionary history of war and are therefore equipped with adaptations to war, and others arguing that war is a recent innovation in human history and that we therefore could not evolve adaptations to war. "War" is understood here in a generic sense, as events in which coalitions of members of a group seek to inflict bodily harm on one or more members of another group. AWAR project aims to contribute to this debate by directly probing the presumed adaptation in contemporary humans via psychological experiments. If we come from a long evolutionary history of war, then our minds should be equipped with evolved machinery enabling the effective navigation of war: efficient, complex, and specialized (sensory, perceptual, cognitive, affective, and behavioral) mechanisms promoting planning, execution, and defense against coalitional aggression.
To probe the existence of the adaptation, we have designed a research program consisting of the following steps (or objectives):
1. Reconstruct the setting of pre-Holocene war.
2. Identify an adaptive problem in the setting of pre-Holocene war.
3. Theorize an adaptation that may help solve this problem.
4. Specify the features of the adaptation via a task analysis.
5. Based on these design features, derive testable hypotheses.
6. Test for the existence of such features (which tests for the existence of the adaptation itself).
7. Examine cross-cultural variation in the outputs of the adaptation.
8. Explore contemporary implications of the adaptation: does it shape people's attitudes toward, and behavior in, modern war or political violence more generally?
To probe the existence of the adaptation, we have designed a research program consisting of the following steps (or objectives):
1. Reconstruct the setting of pre-Holocene war.
2. Identify an adaptive problem in the setting of pre-Holocene war.
3. Theorize an adaptation that may help solve this problem.
4. Specify the features of the adaptation via a task analysis.
5. Based on these design features, derive testable hypotheses.
6. Test for the existence of such features (which tests for the existence of the adaptation itself).
7. Examine cross-cultural variation in the outputs of the adaptation.
8. Explore contemporary implications of the adaptation: does it shape people's attitudes toward, and behavior in, modern war or political violence more generally?
Steps 1-5 have theorized:
1. If war occurred before the Holocene, it took the form of hit-and-run ambushes or surprise encounters during forager.
2. If such ambushes or encounters occurred, then ancestral hominins regularly faced the problem of how not to fall victim to a coalitional attack upon a surprise inter-group encounter.
3. Solving this problem required a psychological adaptation that facilitates detection and evaluation of outgroups upon surprise encounters.
4. The specific features of this adaptation were theorized using a task analysis, an analytical tool borrowed from vision research. An evolutionary task analysis starts by defining the end state and proceeds in specifying the concrete tasks involved in achieving that end state. In this case, the end state is surviving a surprise intergroup encounter. We have identified multiple such tasks, e.g.:
- Task 1: "Detect the outgroup coalition"
- Task 2: "Determine the size of the outgroup coalition"
Each task is accompanied by testable hypotheses, e.g.:
- Task 1: People attend, automatically (non-intentionally), to potential outgroup coalitions (H1)
- Task 2: People determine, accurately (H2) and rapidly (H3), the size of potential outgroup coalitions (i.e. the number of individuals in the coalition)
To test the hypotheses (i.e. Step 6), we have developed and fine-tuned experimental designs based on extant dot-probe and dot-enumeration paradigms. These experimental designs have been adapted for online administration and extensively piloted. The theoretical ideas and the research designs with results have been evaluated by leading scholars across multiple research labs (e.g. the Center of Evolutionary Psychology at the University of California, Santa Barbara) and international conferences (e.g. the Society for Neuroscience annual meeting).
1. If war occurred before the Holocene, it took the form of hit-and-run ambushes or surprise encounters during forager.
2. If such ambushes or encounters occurred, then ancestral hominins regularly faced the problem of how not to fall victim to a coalitional attack upon a surprise inter-group encounter.
3. Solving this problem required a psychological adaptation that facilitates detection and evaluation of outgroups upon surprise encounters.
4. The specific features of this adaptation were theorized using a task analysis, an analytical tool borrowed from vision research. An evolutionary task analysis starts by defining the end state and proceeds in specifying the concrete tasks involved in achieving that end state. In this case, the end state is surviving a surprise intergroup encounter. We have identified multiple such tasks, e.g.:
- Task 1: "Detect the outgroup coalition"
- Task 2: "Determine the size of the outgroup coalition"
Each task is accompanied by testable hypotheses, e.g.:
- Task 1: People attend, automatically (non-intentionally), to potential outgroup coalitions (H1)
- Task 2: People determine, accurately (H2) and rapidly (H3), the size of potential outgroup coalitions (i.e. the number of individuals in the coalition)
To test the hypotheses (i.e. Step 6), we have developed and fine-tuned experimental designs based on extant dot-probe and dot-enumeration paradigms. These experimental designs have been adapted for online administration and extensively piloted. The theoretical ideas and the research designs with results have been evaluated by leading scholars across multiple research labs (e.g. the Center of Evolutionary Psychology at the University of California, Santa Barbara) and international conferences (e.g. the Society for Neuroscience annual meeting).
Theory:
1. Developed an elaborate information-processing model of an adaptation to war.
2. This model has produced 14 novel hypotheses, predicting the existence of certain tendencies in the human mind that allow effectively navigating coalitional aggression.
3. Some hypotheses are general, pertaining to processes studied by scholars in multiple research fields. For example, the theorizing about coalitional formidability assessments has led to the prediction that our visual attention system spontaneously attends to coordinated groups of males and that our enumeration capacity is enhanced when the enumerated objects resemble coordinated groups of males.
Methods:
4. We have developed and extensively piloted several experimental designs. We built on existing paradigms in cognitive psychology but also considerably improved upon them in original ways. Specifically, we have adapted the dot-probe and dot-enumeration paradigms to assess the specific features people attend to in human groups and how people enumerate naturalistic objects (groups of humans), as contrasted to abstract objects (e.g. dots). The generic dot-probe and dot-enumeration paradigms had typically been used in experiments administered in physical labs. We have developed procedures, with publicly available code, to administer these tasks online, e.g. via crowdsourcing platforms such as Prolific. The shift from lab to online research has been conditioned by the COVID-19 pandemic. The pandemic has been a major logistical obstacle and, at the same time, a major cause of innovation for AWAR. Pandemic-related restrictions rendered lab research in many cases unfeasible. Technologies and methodologies have developed rapidly to administer experiments online. The project has capitalized on these developments and by now has produced a number of innovations in the form of cognitive experimental tasks that can be feasibly administered online. To reach these goals, a highly-skilled research team was recruited, including social psychologists, cognitive neuroscientists, and behavioral economists, who have brought a unique mix of skills, from advanced programming of experiments to in-depth expertise in human visual attention. We have also collaborated with scholars from the research-site countries, including Ukraine.
Findings:
5. Twenty-five exploratory experiments (ca. 5000 participants) custom-fitted established attentional bias, enumeration, and rating paradigms for large-scale online administration, and preliminary tested the hypotheses. Seven preregistered studies with probability samples totaling ca. 12,000 participants supported 11 of the 14 hypotheses. Participants automatically attended to, efficiently enumerated, and made nuanced assessments of rapidly presented schematic coalitions. Male participants enumerated the coalitions more rapidly and accurately, female participants perceived them as more formidable, and female and less formidable participants overestimated their numerical size. Combined with multiple tests of alternative explanations, the evidence suggests the existence of specialized adaptations to intergroup coalitional aggression, consistent with the broader hypothesis that human prehistory was characterized by war. The final step in evaluating the overarching hypothesis lies in cross-cultural testing (Step 7). We are currently conducting a study that replicates the core experimental paradigms across 30 countries using representative samples (ca 15,000) in a multi-level framework. We also currently conduct studies that test real world implications of the adaptation in Ukraine (Step 8).
1. Developed an elaborate information-processing model of an adaptation to war.
2. This model has produced 14 novel hypotheses, predicting the existence of certain tendencies in the human mind that allow effectively navigating coalitional aggression.
3. Some hypotheses are general, pertaining to processes studied by scholars in multiple research fields. For example, the theorizing about coalitional formidability assessments has led to the prediction that our visual attention system spontaneously attends to coordinated groups of males and that our enumeration capacity is enhanced when the enumerated objects resemble coordinated groups of males.
Methods:
4. We have developed and extensively piloted several experimental designs. We built on existing paradigms in cognitive psychology but also considerably improved upon them in original ways. Specifically, we have adapted the dot-probe and dot-enumeration paradigms to assess the specific features people attend to in human groups and how people enumerate naturalistic objects (groups of humans), as contrasted to abstract objects (e.g. dots). The generic dot-probe and dot-enumeration paradigms had typically been used in experiments administered in physical labs. We have developed procedures, with publicly available code, to administer these tasks online, e.g. via crowdsourcing platforms such as Prolific. The shift from lab to online research has been conditioned by the COVID-19 pandemic. The pandemic has been a major logistical obstacle and, at the same time, a major cause of innovation for AWAR. Pandemic-related restrictions rendered lab research in many cases unfeasible. Technologies and methodologies have developed rapidly to administer experiments online. The project has capitalized on these developments and by now has produced a number of innovations in the form of cognitive experimental tasks that can be feasibly administered online. To reach these goals, a highly-skilled research team was recruited, including social psychologists, cognitive neuroscientists, and behavioral economists, who have brought a unique mix of skills, from advanced programming of experiments to in-depth expertise in human visual attention. We have also collaborated with scholars from the research-site countries, including Ukraine.
Findings:
5. Twenty-five exploratory experiments (ca. 5000 participants) custom-fitted established attentional bias, enumeration, and rating paradigms for large-scale online administration, and preliminary tested the hypotheses. Seven preregistered studies with probability samples totaling ca. 12,000 participants supported 11 of the 14 hypotheses. Participants automatically attended to, efficiently enumerated, and made nuanced assessments of rapidly presented schematic coalitions. Male participants enumerated the coalitions more rapidly and accurately, female participants perceived them as more formidable, and female and less formidable participants overestimated their numerical size. Combined with multiple tests of alternative explanations, the evidence suggests the existence of specialized adaptations to intergroup coalitional aggression, consistent with the broader hypothesis that human prehistory was characterized by war. The final step in evaluating the overarching hypothesis lies in cross-cultural testing (Step 7). We are currently conducting a study that replicates the core experimental paradigms across 30 countries using representative samples (ca 15,000) in a multi-level framework. We also currently conduct studies that test real world implications of the adaptation in Ukraine (Step 8).