Research Overview:
Humans and other animals do not act symmetrically, and our brains do not function symmetrically. In humans, for example, most are right-handed, and most process language on the left side of their brain. And although these relationships aren’t yet fully understood, scientists have found that studying asymmetrical behaviors can provide us with information about asymmetrical brain function (called lateralization). In this study, we examined different types of behavioral asymmetries in a group of 26 dolphins (e.g., Do they swim clockwise or counterclockwise? Turn onto their left side or right side when minnow-fishing?). It had previously been claimed that dolphins showed primarily “rightward” behavioral asymmetries, similar to human right-handedness. However, looking carefully at several different types of behavior, we discovered that humans interpret the direction of spinning in opposite ways depending on the orientation of the animal, and that previous studies had therefore sometimes used opposite definitions of “right”. Using an orientation-neutral coding system instead, our results did not support a general rightward asymmetry in dolphins, but rather found that different degrees and directions of asymmetry apply to different types of behaviors.
For the full text of the article email research@dolphins.org.
