Final answer:
The internal energy motivating behaviors like eating and playing in cats in the 1930s was referred to as instincts or intrinsic motivation, which are natural and unlearned behaviors.
Step-by-step explanation:
Psychologists and biologists in the 1930s referred to the internal energy motivating behaviors, such as those exhibited by cats, as instincts or intrinsic motivation. These terms describe the natural, unlearned behaviors seen in animals, which could include hunting, napping, purring, and playing. Innate behavior is another term used to describe such actions since they are natural and do not require learning. This means that the energy that drives a cat to behave in certain ways comes from within, often linked to the biological and natural drives for survival, such as the need for food, rest, and reproduction.
For instance, the urge for a cat to chase a mouse is driven by its instinct to hunt, even without being taught. The behavior we observe in animals is often a combination of these innate instincts and responses to their environment, whether it be catching prey, caring for young, or reacting to changes in temperature to maintain homeostasis.