Pay Attention, or Pay the Consequences
Every interview with the neighbor of a heinous criminal seems to start with "He seemed like such a nice guy." Further questioning usually reveals that the neighbor never really noticed the man, with the neighbor ultimately admitting, "He kept to himself." In fact, there were probably many clues that Mr. X was not such a nice guy after all. It's just that no one ever paid much attention.
Decisions are no better than the information on which they're based. Incorrect or incomplete information can lead to an incorrect conclusion—garbage in, garbage out. So before you can effectively read people, you need to gather reliable information about them. You can do this by using your eyes, your ears, and at times even your senses of touch and smell. When people fail to be attentive and focused, the consequences can be regrettable.
It's not hard to recall occasions when we've been inattentive to important clues. We may hire a day-care provider without spotting the faulty latch on her backyard fence, noticing how she ignored the children under her care as she spoke to us, or paying attention to her poor grammar. Yet each of these factors could have a critical impact on our child's well-being and development. We may not notice the flushed face and ever-so-slightly slurred speech of an employee who returns from a long lunch, but these may be clues he's been drinking—maybe drinking too much. This type of critical information is usually available to you—if you just take your time and pay attention.