I would say Social Cognition
Answer:
Well, <em>I'd</em> <em>say</em> because of bipedalism (standing and walking up-right).
Explanation:
Favoring vision among our other four senses is seen as a consequence of how human evolution has developed so far. Thanks to bipedalism we could free our hands from the ground, then, we started using tools better; we gained a way of saving energy when commuting for long distances; and we allowed our selves to have a wider field of vision, which helped us in many ways, but especially in preventing attacks from predators.
This last evolutionary feature is what originated our nowadays-very-accute vision.
