The Demographic Benefits of Belligerence and Bravery: Defeated Group Repopulation or Victorious Group Size Expansion?
2011

The Benefits of Fighting: How Belligerence and Bravery Help Groups Survive

publication Evidence: moderate

Author Information

Author(s): Laurent Lehmann

Primary Institution: University of Lausanne, Lausanne, Switzerland

Hypothesis

What are the conditions under which coalitional aggression evolves in natural populations?

Conclusion

The study suggests that belligerence and bravery can evolve in groups, especially when defeated groups can be repopulated by victorious ones.

Supporting Evidence

  • Intraspecific coalitional aggression is common in many animal species, including humans.
  • Belligerence increases the likelihood of a group attempting to conquer another group.
  • Bravery enhances a group's chances of winning battles against other groups.
  • The model indicates that the selective pressures on these traits are stronger when defeated groups can be repopulated.

Takeaway

Animals sometimes fight in groups to take over resources or mates, and this study looks at how being brave or aggressive can help them win.

Methodology

The study uses a mathematical model to analyze the coevolution of belligerence and bravery under different demographic scenarios.

Limitations

The model assumes a simplified demographic structure and may not capture all complexities of real-world interactions.

Digital Object Identifier (DOI)

10.1371/journal.pone.0021437

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