What does the hand/walking theory emphasize?

• A. Upright walking hindered brain growth
• B. Upright walking freed hands for complex tasks leading to planning
• C. Hands are unimportant to cognitive evolution
• D. Brain evolution preceded hand use

Answer: (B)

The hand/walking theory emphasizes that becoming bipedal freed the hands to manipulate objects and perform complex tasks, which requires planning and foresight. With hands available for tool use and deliberate action while walking, early humans could engage in more advanced problem solving and sequential thinking, driving cognitive development alongside physical changes. This view sees tool use and planning as sparks that help push brain evolution, rather than brain size growing first or hands being unimportant. The other options don’t fit because they either deny the link between free hands and cognition, suggest brain changes come before hand use, or claim upright walking hindered brain growth.