Tuesday, November 5, 2013
Humans who are faced with difficult choices are often tempted to simply opt out of making a choice, especially when they realize that they cannot easily resolve their uncertainty as to which choice is the better choice. Some researchers consider this ability to opt out as an indicator of “meta-cognition”, a term used to describe “thinking about thinking”. Instead of plowing ahead with a random choice, humans can recognize that they lack adequate information and choose not to make a decision. Humans are not the only animals who engage in meta-cognition. Recent studies have shown that dolphins or non-human primates also have the capacity for meta-cognition and when faced with difficult decisions may also choose to opt out of the decision-making process.
The new study “Honey bees selectively avoid difficult choices” published on November 4, 2013 in the Proceedings of the National Academy of Sciences suggests that honey bees can exhibit complex decision making skills and opt out of making difficult choices. The researchers Clint Berry and Andrew Barron studied the behavior of honey bees in containers who were given two choices: flying towards targets containing either a reward (sweet sucrose solution) or a punishment (bitter quinine solution), as well as an opt-out choice in which they could exit the container. In the first stage of the experiment, the bees were trained to recognize the targets by using horizontally drawn reference lines and placing the reward and punishment targets clearly above or below the reference lines. The bees gradually learned to distinguish between reward and punishment by using the reference lines. In subsequent experiments, the researchers challenged the trained bees by making it more difficult for them to distinguish between reward targets and punishment targets. They placed the targets closer and closer to the reference line, to the point where it even became impossible for the bee to "guess" which target would contain the sweet sucrose solution and which one was the bitter quinine solution. As this distinction became more difficult, an increasing number of bees simply chose to not make a decision at all and instead opted out of the test by flying into another container via an "exit hole".
This study shows that bees have some degree of adaptive or complex decision making capacity. Bees can learn and remember different stimuli, and that the difficulty of the decision influences their behavior. It also has some strengths such as the straightforward experimental design and the inclusion of control experiments, such as the fact that the researchers alternated the positions of rewards and punishments to make sure this was not a confounding factor.
However, it would be premature to call this study evidence of meta-cognitive thinking, as suggested in the press release by the university. There are important limitations to this research, such as the fact that the study conclusions regarding the decision-making of bees is based on merely ten individual bees, some of whom responded very differently from each other. This is rather surprising since the experimental set-up appears fairly simple and a higher sample size could have bolstered the marginally significant results. Furthermore, it is not possible to interrogate bees to ascertain their motivations or rationale. Merely opting out of a difficult choice by flying into a different container is not really sufficient to invoke “meta-cognition”, a complex process that should only be used when one can investigate the cognitive process itself and understand how decisions are made. The discussion section of the paper even goes into speculations about neuronal pathways that bees may use, but at no point were neuronal pathways even assessed in the study.
In summary, this is an interesting study that informs us about the complex learning capacity of bees and reminds us that non-mammals may have learning, memory and decision making skills that need to be investigated. Its major limitations make it difficult to draw definitive conclusions about “meta-cognition” in bees, but hopefully, this study will inspire future research that investigates non-mammalian decision-making in more depth.Clint J. Perry, & Andrew B. Barron (2013). Honey bees selectively avoid difficult choices Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1314571110