If you’re a CEO, you’re being watched.

A little more than you usually are, anyway. Research led by two Harvard Business School professors is attempting to find keys to the CEO’s success through close study not of the exec’s decisions or of others’ opinions but of what they say and how they look when they say it. Right down to their smirks and smiles.

Using video interviews with 130 leaders, the researchers applied machine-learning tools to scrutinize the words that CEOs chose, how much they tended to stray from topic to topic, the positivity or negativity of the words they used, and their facial expressions. The era of machine learning has provided a boost for that last task. As an HBS report on the study explains, “This type of analysis had typically been done by human coders, but the researchers discovered that computer analysis proved to be a robust, yet fast and cheap alternative to generating emotional data.”

The study is a reminder, in case you needed one, that how a CEO communicates in person matters.

The process distilled CEOs into five distinct temperamental categories: excitable, stern, rambling, dramatic, and melancholy. The research is preliminary, and none of the categories are, in themselves, bad. After all, the video interviews were made of executives who had proven records of success.

And there were no earthshaking conclusions from the research. Those “with a higher dramatic score showed less merger and acquisition activity in the year following the interview,” according to the report on the study. But the researchers also note that their work shows that leadership style seems to be a function both of what you say and how you say it: “In general, the observed styles do not seem to emerge fully without the inclusion of both text- and video-based measures, supporting the idea that both verbal and paraverbal communication are crucial to establishing a communication style,” the working paper from the study [PDF} says.

I don’t suspect that future research on this front will deliver too many surprises—though we might get a spike in “Are You a Melancholy Leader?” features, complete with images of whatever you get when you search on “Hamlet” in a stock-photo database. But the research is worth paying attention to, for two reasons.

First, it’s a reminder, in case you needed one, that how a CEO communicates in person matters. Just to pick a recent example: Last week, Associations Now reported on a study showing that a CEO’s face-to-face engagement in PAC efforts has a big impact: “Engaged leaders both boost a PAC’s visibility and increase its fundraising capabilities,” according to the article, and among the biggest boosters were attending PAC events and direct solicitations of the board. Being seen matters.

Second, more is likely to be made of how you’re seen, now that we’ll increasingly have cheaper and faster tools to make that assessment. “Anticipatory intelligence”—big data, machine learning, AI, and so on—is one of the change drivers in ASAE’s ForesightWorks research initiative, and it can be just as meaningful for how an association looks at itself as for how it looks at its industry. The typical association CEO makes plenty of public appearances, and in time they may all be grist for the big-data mill.

As the study’s researchers point out in the conclusion to their report, organizations “frequently post videos to open-access video platforms such as YouTube, many of which contain recordings of executives speaking and interacting. These videos can reveal a great deal about a CEO’s leadership approach through verbal and nonverbal patterns that have been unexplored as yet. … In addition, researchers might use videographic data to predict executives’ ascension into CEO positions. The tools we present in our analysis would facilitate research into these new questions.”

None of this should make you, as a leader (or an aspiring one), anxious to change your public image—to make sure you look more “dramatic” and less “rambling,” lest the bots tell you how disappointed they are in your comportment. Authenticity is still more valuable than any other personality category a leader can be slotted into.

But it’s a reminder that communication is an essential skill for a CEO, and one that’s being increasingly studied. The dystopian novel about all this would have an executive being fired for frowning at the wrong moment. But in the real world, an executive’s understanding that being open, honest, and clear about what his or her organization does is one more valuable piece of the leader’s toolkit.

How do you think about personal communication as a leader, and what have you done to improve your communication style? Share your experiences in the comments.

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