Why Cooperation Exists in a Selfish World?

Hong-Hue Thi Nguyen

Ho Chi Minh City

27-05-2026

© Wix

How does natural selection promote cooperative behavior? If two animals compete for food, mates, or survival, why would one individual sacrifice resources to help another? Intuitively, selfish individuals seem more likely to gain an advantage by taking benefits without paying the costs of cooperation.

This apparent contradiction—how cooperation can persist in a world shaped by competition—has long been considered one of the central paradoxes of evolutionary biology and has intrigued scientists for decades (Axelrod & Hamilton, 1981; May, 1987).

Many explanations have emerged. Individuals may cooperate with relatives because they share genes (Hamilton, 1963). Cooperation can also arise through reciprocity: I help you today because you helped me yesterday (Sachs et al., 1963). Some animals build reputations and cooperate because others remember their behavior. Still other explanations rely on social networks, group structures, or recognizable traits that help identify trustworthy partners (Ohtsuki, 2006).

Yet many of these mechanisms require surprisingly sophisticated abilities. Remembering previous interactions, tracking reputations, or recognizing relatives can impose substantial cognitive costs. Meanwhile, cooperation is found even in microorganisms and simple organisms lacking complex brains.

A recent study on PNAS suggests that cooperation may emerge from something more fundamental: differential responses, or what might be called opponent-specific behavior (Morozov & Feigel, 2026).

Rather than treating every interaction identically, organisms may simply respond differently depending on who—or what—they encounter.

This may sound trivial, but its implications are profound.

Microorganisms can produce slightly different cellular states through random molecular processes. Animals may react differently to individuals based on appearance, behavior, or familiarity. Some organisms may cooperate more with certain partners and less with others. Over time, natural selection and mutation can reinforce these varying responses, allowing cooperation to emerge without sophisticated planning or moral reasoning.

Examples of this pattern appear throughout nature.

Yucca plants depend on specialized moths for pollination while providing food for moth larvae. Yet some moths “cheat,” laying eggs without properly pollinating flowers (Pellmyr & Thompson, 1992; Sachs et al., 2004). Certain birds, such as superb starlings, have been observed helping unrelated individuals despite opportunities to assist relatives instead. Similar dynamics may exist among pollinators, marine symbioses, and even yeast cells.

Viewed through the lens of Granular Interaction Thinking Theory (GITT), these findings become particularly interesting.

GITT suggests that reality is composed not of isolated entities but of dynamic information interactions occurring at multiple granular levels (Vuong, 2025; Nguyen, 2026). The value or meaning of an interaction does not reside entirely within an individual organism itself; rather, it emerges through relationships.

From this perspective, cooperation is not necessarily a fixed personality trait—organisms are not simply “cooperative” or “selfish.” Instead, cooperative behavior may emerge from interactions among informational units.

A bee visiting one flower carries information about reward expectations. A flower carries information about nectar availability. A bird observing another bird carries information about past encounters or visible signals. Different interactions generate different informational environments and therefore different behavioral outcomes.

Imagine trying to predict an entire forest by studying a single tree. The tree matters, but understanding the forest requires observing countless interactions among roots, fungi, insects, birds, rainfall, and sunlight. Likewise, understanding cooperation may require moving beyond isolated individuals toward networks of information exchange.

Perhaps evolution’s secret is not that cooperation is better than selfishness, but selfishness and cooperation were never entirely separate in the first place.

Under GITT, life may be less like independent actors competing on a stage and more like countless conversations unfolding simultaneously—where cooperation emerges not from perfect goodness, but from the dynamic ways selfish living systems learn to respond to one another (Khuc & Nguyen, 2026).

References

Axelrod, R., & Hamilton, W. D. (1981). The evolution of cooperation. Science, 211, 1390–1396. https://doi.org/10.1126/science.7466396

Hamilton, W. D. (1963). The evolution of altruistic behavior. The American Naturalist, 97, 354–356. https://doi.org/10.1086/497114 

Khuc, V. Q., & Nguyen, M. H. (2026). Cultural Additivity Theory. Available at SSRN 6767760. https://ssrn.com/abstract=6767760

May, R. M. (1987). More evolution of cooperation. Nature, 327, 15–17. https://doi.org/10.1038/327015a0

Morozov, A. V., & Feigel, A. (2026). Emergence of cooperation due to opponent-specific responses in Prisoner’s Dilemma. PNAS, 123(21), e2513282123. https://doi.org/10.1073/pnas.2513282123

Nguyen, M.-H. (2026). Ayn Rand and Kingfisher on zero-carbon bombs and a

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Ohtsuki, H., et al. (2006). A simple rule for the evolution of cooperation on graphs and social networks. Nature, 441, 502–505. https://doi.org/10.1038/nature04605

Pellmyr, O., & Thompson, J. N. (1992). Multiple occurrences of mutualism in the yucca moth lineage. PNAS, 89, 2927–2929. https://doi.org/10.1073/pnas.89.7.2927

Sachs, J. L., et al. (2004). The evolution of cooperation. The Quarterly Review of Biology, 79, 135–160. https://doi.org/10.1086/383541 

Smith, J. M. (1964). Group selection and kin selection. Nature, 201, 1145–1147. https://doi.org/10.1038/2011145a0

Vuong, Q. H. (2025). Wild Wise Weird. AISDL. https://books.google.com/books?id=C5dDEQAAQBAJ