Let's make this easy.

People, whether they know it or not, walk around with checklists in their heads. When they enter a room or meet someone or hear a song or see a movie, they immediately run through a list of criteria and then conclude "like or dislike."

Such checklists are burned into your brain. They are why you gravitate toward a certain painting in a museum or turn down 44th Street rather than 45th. These are reactions to stimulus that are barely conscious or thought-out but legitimate nonetheless.

People in marketing and "human resources" carry checklists on their sleeves. They carry their musts with them and wear them as a frontlet. Never is the discussion about "do I like this ad?" It's almost always about does the ad do this, this, this and this. Will my field people like it, my salesforce, my boss.

HR in their zeal for 360 reviews gives you about 12 categories on which to rate people. They could just ask "Do you want them on a pitch?" "When it's late Friday and the work is due Monday and you're nowhere, do you want them in the room."

Brains work pretty well in general. We intuitively avoid danger--that's how our species has survived for the last couple million years (or last few thousand if you're Sarah Palin.)

However, brains don't work if they think too hard.