Which of the following is considered an adaptive theory explaining why humans sleep?

• A. The energy conservation theory, which claims sleep reduces energy expenditure
• B. The information consolidation theory, which states sleep aids in processing and storing memories
• C. The evolutionary theory, which suggests sleep protects us from dangers during periods of vulnerability
• D. The restorative theory, which proposes sleep helps the body repair and rejuvenate itself

Answer: (C)

Verified step by step guidance

1. Step 1: Understand what an adaptive theory of sleep means. Adaptive theories explain sleep in terms of evolutionary advantages, focusing on how sleep behaviors have helped humans survive and reproduce over time.
2. Step 2: Review each theory option and identify whether it emphasizes evolutionary benefits or other functions of sleep. For example, the energy conservation theory focuses on saving energy, which can be adaptive, but is more about physiological efficiency.
3. Step 3: Recognize that the evolutionary theory explicitly states sleep protects us from dangers during vulnerable times, which directly ties to survival and adaptation in an evolutionary context.
4. Step 4: Differentiate the other theories: the information consolidation theory relates to memory processing (a cognitive function), and the restorative theory focuses on bodily repair, both important but not primarily about evolutionary adaptation.
5. Step 5: Conclude that the evolutionary theory is the adaptive theory because it explains sleep as a behavior shaped by natural selection to enhance survival by reducing exposure to danger.