Introducing Light-O1, a whole-body intelligence model scaled through human action pretraining. • Human action at scale: We learn from structured human actions recovered from internet videos, capturing a scale and diversity that robot data collection alone struggles to match. • Cross-embodiment transfer scaling law: Scaling human action pretraining yields power-law reductions in prediction error across embodiments. • Whole-body intelligence: Adapted to different humanoids, Light-O1 coordinates movement, posture, and manipulation to autonomously perform household tasks.