How Manipulation Becomes Altruism: A Study

Manipulation may lay the groundwork for ultimately helpful and even altruistic behaviors, a new study published in the journal American Naturalist explains.

Manipulation, in this case, is defined as one party changing the behavior of another in a way that benefits the manipulator with the possibility of inflicting harm on the manipulated, and can be seen all the way down to a cellular level.

One famous example from nature is the parasitic roundworm Myrmeconema neotropicum. Once ingested by the ant Cephalotes atratus, the parasite causes the ant's abdomen to take on a red hue that leads birds to ingest them thinking they are berries. The parasite is then spread through the birds' droppings, which the ants forage and feed to their larva, thus creating a cycle of manipulation.

In the new study, researchers developed a mathematical model for the evolution of manipulated behavior and then applied it to organisms whose societies are based on one reproductive queen, such as wasps, ants and bees.

Specifically, the model included mothers producing two broods, the first of which she manipulated to stay on site and wait for the birth of the second brood in order to help raise it. However, the first group of offspring was able to resist manipulation, which may consist of poor feeding or aggressive behavior on the mother's part.

What the scientists discovered was that those offspring who resisted manipulation put themselves at risk of failing to evolve in the case that the cost of resistance was high. Thus, in a very real sense, altruism was coerced through manipulation.

These findings, says lead author Mauricio Gonzalez-Forero, who conducted the study while a graduate assistant at the National Institute for Mathematical and Biological Synthesis, are corroborated by observations of such colonies, "where helping is often coerced through aggression or differential feeding" that appears "consistent with these results."