- In the standard anatomical position, the body is standing upright, facing forward, with the arms at the sides and the palms facing forward.
- In this position, the thumb is located on the lateral side of the hand, while the little finger is on the medial side.

Key points to understand:
- Medial means toward the midline of the body.
- Lateral means away from the midline of the body.
- Since the thumb is positioned away from the midline compared to the little finger, it is considered lateral.
- Anterior refers to the front of the body, which is not applicable in this context because we are describing side-to-side orientation.
- Proximal means closer to the point of attachment or origin, which describes position along a limb rather than side-to-side relation.

Therefore, in relation to the little finger, the thumb is positioned laterally.

Reference: Gray's Anatomy, 41st Edition, Upper Limb Chapter, Page 735