Which theory explains human behavior as motivated by automatic and unlearned responses?

The choice that explains human behavior as motivated by automatic and unlearned responses is instinct theory. This theory posits that certain behaviors are innate and driven by biological instincts, which are hardwired into an individual's nature. Instinctive behaviors are not learned or taught; rather, they emerge naturally as a response to specific stimuli. For example, basic survival instincts, such as a newborn's reflex to suckle, exemplify how instinct theory operates. This aligns with the idea that such responses occur without prior experience or conscious thought, demonstrating the automatic nature of these behaviors.

The other theories do not focus on automatic or unlearned responses. Synthesis theory generally involves integrating various elements into a coherent understanding, while comprehension theory relates to the processes of understanding and learning. Cultural theory emphasizes how behavior is shaped by social and cultural contexts, which involves learned behaviors rather than instinctive responses. Thus, instinct theory is the most fitting explanation for behavior driven by innate and unlearned responses.