As a professor at the MIT Media Lab, Alex “Sandy” Pentland naturally knows how to take a quantitative and technological approach to research questions. But when Dr. Pentland and his colleagues began applying technological tools to a question of human behavior—how people use nonverbal communication cues—the results were startling. And powerfully instructive for managers.

Many of Dr. Pentland’s findings—based on data from a device he calls a “sociometer,” a wearable, badgelike contraption that can continuously measure various nonverbal aspects of people’s interactions—have implications for both how executives communicate and how they understand what is being communicated to them. He spoke with MIT Sloan Management Review senior editor Martha E. Mangelsdorf for the Business Insight Journal Report.

BUSINESS INSIGHT: In your new book, “Honest Signals,” you discuss a number of unconscious, nonverbal ways that humans communicate with one another. Let’s talk about four you focus on: activity, interest, mimicry and consistency.

DR. PENTLAND: These signals are really qualitative readings of brain state. Take activity. Everyone has an autonomic nervous system; it’s the oldest part of your nervous system, the fight-or-flight part. When you get excited about something, it gets aroused. What happens then is you become more active and you have more nervous energy. So I built computer tools that can read how much nervous energy you have.

Similarly, as a measure of interest, people pay attention to each other, and you can read that from the timing between people who are in conversation. If two people are talking together and each one is anticipating when the other will pause and jumping in exactly at that point and leaving no gaps, then they’re paying a great deal of attention to each other.

Humans also have a system called a mirror neuron system. Strangely enough, when you watch somebody move, a part of your brain that corresponds to the same movement lights up. And when people mimic each other’s gestures when in conversation, research has shown that it’s very definitely correlated with feelings of trust and empathy. Mimicry creates the sense that people are on the same page.

And the final one I focused on was fluency, or consistency. Think of Tiger Woods and his golf swing. There’s a sort of fluidity about it that just says, “This guy’s an expert.” And people have the ability to read that. Consistency in tone or motion tells you who really knows what they’re