First, we perceive the world of objects as essentially separate from the world of minds, making it possible for us to envision soulless bodies and bodiless souls. This helps explain why we believe in gods and an afterlife. Second, as we will see, our system of social understanding overshoots, inferring goals and desires where none exist. This makes us animists and creationists.
When we see a complex structure, we see it as the product of beliefs and goals and desires. Our social mode of understanding leaves it difficult for us to make sense of it any other way. Our gut feeling is that design requires a designer—a fact that is understandably exploited by those who argue against Darwin.
It's not surprising, then, that nascent creationist views are found in young children. Four-year-olds insist that everything has a purpose, including lions ("to go in the zoo") and clouds ("for raining")... And when asked about the origin of animals and people, children tend to prefer explanations that involve an intentional creator, even if the adults raising them do not. Creationism—and belief in God—is bred in the bone.