Temperament is something we're born with -- it's a set of traits that makes each of us unique, and it's a powerful factor in determining how we react to the world. The way a child approaches a new situation is one example of temperament at work.
Consider, for example, three 2-year-olds entering their classroom on the first morning of daycare. Rahim and his mother open the door and scan the room. Within minutes, Rahim rips off his coat and abandons his mom to join the other kids building with blocks.
When Frank and his dad arrive at the classroom, Frank spends a long time leaning into his dad's leg and refuses to take off his coat or hat. After watching the other kids for a while, he inches away from his dad to get a closer look at a table where kids are working on puzzles. At that point, Frank's dad suggests that he join them. Frank takes his dad's hand, and they walk together to the puzzle table. Frank sits down next to another child and gets to work.
Carlos speeds into the room ahead of his grandmother -- no time to waste looking around to check out what's going on. He charges up to two boys who are crawling on the floor, grabs one of the trucks, and yells, "Mine!"