Janis wants to keep a clean home so she can have friends over. although cleaning isn't the most enjoyable activity to her she discovers something interesting: when she sweeps the kitchen she then feels like putting more effort into cleaning the rest of the day. how might we describe this in psychological terms

This can be described as a commitment.

Explanation:

From a psychological point of view, we can say that when Janis swept the kitchen's floor, she committed herself to have a clean house so that she can invite her friends. She is directing her activities to reach a goal and is easier because after sweeping the kitchen she is mentally predisposed to reach her goal of keeping the house clean.