Some people make quick, seemingly impulsive decisions while others take their time, meticulously researching all possible choices. Neither way is wrong, as they both have their uses given the right setting. However, fast decision makers are more often inaccurate than those that make decisions more slowly. Making a decision is also expensive, as the nervous system requires lots of energy to function. Is one strategy more expensive than the other? To find out, Catherine Tait, Adam Chicco and Dhruba Naug of Colorado State University, USA, measured how much energy the brains of honeybees (Apis mellifera) consumed while they were making decisions.
First, Tait and Naug needed to train the bees. To do this, the researchers gave the bees a sugar water reward if they extended their mouthparts when they had a particular scent wafted over them, but gave the bees saltwater instead if they were presented with a different aroma. The bees who learned that the first scent meant a sugary treat the quickest were considered fast learners. But faster learning comes at a cost. An hour later, when the scientists switched which scent gave a reward, the fast learners took longer to grasp that the reward-giving smell had changed. But could the fast learners just have bigger brains?
The answer isn't quite so simple. After performing the painstaking task of measuring how much each bee's brain weighed, Tait and colleagues discovered that the fast learners do, in fact, have larger brains. However, the team knew from previous research that bigger brains use less energy, probably because they are less densely packed with nerves or because the nerves don't fire as frequently. So, do the fast-learning bees have brains that are big but aren't as energy efficient?
The researchers measured the metabolic rates of the bee brains and found that bigger brains burned less energy than smaller ones. So, the big brains of fast learners are more energy efficient, but these faster bees still seemed to use more energy overall. While being a fast learner might seem ideal, these bees are more inaccurate and less flexible at incorporating new information when making their decisions. Given these issues, and the fact that they use more energy overall, making snap decisions can certainly come with a cost.
