Focus on the eyes. Beware of too much eye contact, also known as "stalker stare." Liars, knowing that good eye contact is a sign of honesty, may try too hard to appear honest with unnaturally fixed eye contact. Watch for wide eyes accompanied by an open mouth, which indicates fear or surprise, while wide eyes with a close mouth suggests innocence or cluelessness. Droopy eyes can mean lazines, drowsiness or flirtation.
Observe the blink rate. A rapid increase in blinking often indicates stress or nervousness. One researcher noted that President Bill Clinton, while answering a tough question during a debate, went from a blink rate of 43 blinks per minute to 117 per minute.
Watch the eyebrows and nose. While raised eyebrows can suggest surprise or disbelief, it's also a way to greet someone. A crinkled nose, on the other hand, conveys quite the opposite — that you want someone to go away.
Notice the interaction between the mouth, lips and tongue. Biting an upper lip shows nervousness or possible insecurity. Biting a lower lip can also suggest nervousness, but may also be flirtation. Pursed lips, especially when accompanied by a raised eyebrow, shows contemplation or uncertainty about something someone said. A hyperactive tongue, such as in licking lips, denotes nervousness and stress. But this, too, can be a sexual signal.
Watch the head position. A person's chin, especially, serves as a barometer for gauging a person's attitude. A raised chin suggests that a person feels superior and looks down on others, either from insecurity or excessive pride. A chin tucked inward, conversely, is a protective gesture and shows that a person wants to be smaller. A chin level with the ground, though, reveals a level head and that a person feels comfortable in her own skin.