The average human blink rate varies from about 17-25 blinks per minute (BPM).
As we become interested, curious, entertained or otherwise focused on a stimulus, our blink rate can slow significantly to around 7-10 BPM.
During stressful times and emotionally pressing events, our blink rate can soar up to about 50 BPM without us even realizing it. Try to even REMEMBER taking the SAT's without blinking a lot.
How does this apply to real human life?
As you become more interesting or your conversational topic starts to gain more focus and attention, you will actually see the blink rate of your subject(s) start to decline. This isn't a skill you will have to practice much. Within two days, you can likely become very proficient at observing this behavior.
What happens when you're talking and the subject's blink rate starts to get faster and more frequent? You're boring someone to death or the topic is causing emotional stress.
Start using your new skill today!
Remember the law of compounding effects with body language: "The more small bites you take when learning, the less attention they cost over time, so you can spend your limited supply of attention on more important behaviors."
Would someone else love this?