Some psychologists believe that an organism's behavior is motivated by the need to achieve a state of balance in which the body functions effectively—a state called .

Homeostasis

Explanation:

Some psychologists believe that an organism's behavior is motivated by the need to achieve a state of balance in which the body functions effectively—a state called homeostasis.

Homeostasis is the ability for an organism to be able to maintain an internal state that is relatively stable even though there are changes happening around.

Living organisms regulate their internal environment. This is done in order for them to be able to survive and also process their energy.