Laterality
Laterality is the tendency to prefer one side of your body over the other, like being right-handed.
A kitchen counter has two sides: left and right. Most cooks keep their main tools on one side. The other side stays mostly clear. The brain works the same way, picking one hand to lead over the other.
Explaining laterality by grade level
Write your name with each hand. One hand feels much easier than the other. Your brain picks a favorite side for most tasks. Your feet, eyes, and ears have a favorite side too. Even dogs and mice tend to favor one paw.
Projects that explore laterality
Most people prefer one side of their body. About 90% of people are right-handed. But that preference may not carry over to feet or eyes. You can test which hand writes and which foot kicks. Some people favor different sides for different tasks.
Laterality can be measured by giving the same animal more than one physical task. You test 20 dogs using two tasks: a handshake and a biscuit pouch. You repeat each task four times per dog. The combined results reveal whether dogs tend to prefer one paw or use both equally.