Increasing the number of options can paradoxically lead to worse decisions, a phenomenon known as cognitive overload. This happens when an individual decision-maker attempts to digest information exceeding its processing capacity. Highly integrated groups, such as social insect colonies, make consensus decisions that combine the efforts of many members, suggesting that these groups can overcome individual limitations. Cognitive overload is a growing issue for human decision-making, as unprecedented access to data poses new challenges to individual processing abilities. Human groups also solve difficult problems better when each group member has only limited access to information. It has long been recognized that collective choice can improve accuracy by averaging out the random errors of inaccurate individual decisions. The advantage we find here is different: rather than combining many essentially identical choices, colonies truly distribute their decision-making. No worker must carry out the full task of assessing and comparing all options, allowing the colony as a whole to process more information, more effectively.
Read also: Colony-level Cognition