According to core knowledge theory relating to living things, which cue is used to distinguish living from nonliving objects?

• A. Movement
• B. Color
• C. Temperature
• D. Size

Answer: (A)

Movement signals self-generated action, which is a defining cue humans use to separate living from nonliving objects. In core knowledge theory, people—starting in infancy—are tuned to animate motion: things that move on their own with apparent purpose show internal organization and agency typical of life. Nonliving things can move, but only when acted upon by an external force; they don’t exhibit ongoing, self-propelled activity.

Color, temperature, and size aren’t reliable indicators. Colors and sizes appear in both living and nonliving things; temperature can be the same across objects whether alive or not. Because these cues don’t consistently map to life, movement remains the most informative sign to distinguish living from nonliving. For example, a dog running on its own is alive, whereas a rolling rock moves only due to an outside push.