Scientists recently performed a study comparing the complexity of brain function in social insects as opposed to solitary insects. They found that unlike vertebrate species, which evolve to have increasingly complex brains the more complex the society becomes, social insects that share information among the members of the colony reduces their need for complex brain function and the complexity of their cognitive brain functioning actually decreased as the complexity of their societies increased.
In vertebrate animal societies as the social environment grows more complex over generations the cognitive abilities of the individuals in that society are forced to adapt and also become more complex. More complex social societies tend to have an increased amount of competition between their individuals. As individuals have to navigate more and more challenges such as conflict over resources, their cognitive abilities are forced to evolve in order to continually sharpen their intelligence so they can continue to survive in more and more complex societies.
However, in social insect species the colony tends to be made up of family groups, with the children staying to help their parents, and while there may be some conflict in these colonies, the survival of the group depends on their ability to work together as a cohesive unit. The more cooperative structures of social insect colonies end up affecting the evolution of the brain differently.
Researchers studied the brains of 29 related species of wasps from Costa Rica, Ecuador and Taiwan. They studied both solitary and social species that had varying colony sizes and structures. They found that the solitary species had evolved to have larger brain parts associated with complex cognition used for such things as spatial memory, associative learning, and multi-sensory integration. On the other hand, the social insect species had less complex cognitive function. The researchers believe that this is because social insect colony members are able to rely on group members, meaning they don’t have to invest as much energy in more complex individual cognitive functions. These social species evolved to survive cooperatively, utilizing such things as sharing information among colony members, which reduces the need for individual cognition.
Do you think humans could have evolved in this manner if we had more cooperative societies, or is that impossible due to our conscious brains? How might our humans society be different if our brains had evolved in the same way as our societies became more complex?