"Imagine that you are a hominid walking along the savanna of an African valley three million years ago. You hear a rustle in the grass. Is it just the wind or is it a dangerous predator? Your answer could mean life or death.
If you assume that the rustle in the grass is a dangerous predator but it turns out that it is just the wind, you have made what is called a Type I error in cognition, also known as a false positive, or believing something is real when it is not. That is, you have found a nonexistent pattern. You connected (A) a rustle in the grass to (B) a dangerous predator, but in this case A was not connected to B. No harm. You move away from the rustling sound, become more alert and cautious, and find another path to your destination.
If you assume that the rustle in the grass is just the wind but it turns out that it is a dangerous predator, you have made what is called a Type II error in cognition, also known as a false negative, or believing something is not real when it is. That is, you have missed a real pattern. You failed to connect (A) a rustle in the grass to (B) a dangerous predator, and in this case A was connected to B. You’re lunch. Congratulations, you have won a Darwin Award. You are no longer a member of the hominid gene pool."