You may have heard the claim that left-handed people are smarter than right handed people. Specifically, it seems that left-handed people are over represented in musicians, architects and art and music students. Why this might be isnt entirely clear, but it is possible that it has something to do with the left-handed brain being larger and having greater connectivity than the right-handed brain.
The reason some people are left-handed while others are right-handed is because of brain lateralization: the division of the brain into two hemispheres. However, we're not the only animals that have brain lateralization; many animals have a preference for using either their right or left leg, paw, eye, foot, or ear, for example. Cats are generally right-pawed, dogs are pretty evenly split between being left- or right-pawed, while wall lizards are generally left-eyed.
However, how does being right- or left-haded/eyed/eared actually affect how we think? A recent study looked into this using the rainbow fish. Using wild and captive individuals of this Australian fish, the researchers looked to see if whether the fish was left- or right- eyed would affect its ability to learn. Left-eyed fish turned out to be faster learners than right-eyed fish. Also, fish that were hatched in the wild tended to be faster learners than captive-bred fish. Whether the fish was male or female had no effect on their ability to learn.
Why it might be that the left-eyed fish are faster learners isnt entirely clear. Hopefully more studies of this type with other animals will help us gain a greater understanding of what exactly is going on.
Jimi Hendrix statue: Bleachers
Rainbowfish: Roan Art
Bibost, A. L., & Brown, C. (2014). Laterality influences cognitive performance in rainbowfish Melanotaenia duboulayi. Animal cognition, online first. DOI: 10.1007/s10071-014-0734-3