There’s a saying in cognitive science that even the most skilled listeners can track the mental states of no more than three to six people at once. Some historical anecdotes might claim that great leaders – Napoleon, for instance - could listen to and understand eight, ten, or even more than ten people simultaneously. But modern science suggests that’s beyond the natural capacity of most individuals. 

Still, such anecdotes point to an intriguing truth about the human mind: understanding what others are saying isn’t just about hearing the words — it’s about reading the thoughts and feelings behind them.

Mental states 

To truly grasp an individual’s message, we need to interpret the mental state that shaped it: the speaker’s intentions, beliefs, emotions, knowledge, and assumptions. This capacity, known as ‘Theory of Mind’, is the foundation of what psychologists call ‘mentalizing’ — the conscious, active process of imagining and understanding what’s going on in someone else’s mind. And, as I’ve pointed out, research shows that most adults can keep do that for only three to six people at a time. If someone truly could understand more than that simultaneously, it would be an extraordinary feat of mentalizing.

In their book, The Social Brain, Cammilleri, Rockey and Dunbar note that our capacity for mentalizing shapes everything from the number of friends we can maintain, to how we understand complex writing, humour, and even organizational structures and processes. In short, the ability to read minds — or the inability to — directly affects the quality of our conversations, collaborations and, what I’d like to focus on here: work.

Do people understand you?

In business, communication is ultimately about being understood, not just about saying something. That’s why being able to gauge how others are receiving your message — your ability to mentalize — can determine the success, or failure, of any conversation/meeting/presentation.

Yet too many workplaces focus too much on the visual during presentations: how slides and documents look. In doing so, they overlook the non-verbal cues — tone of voice, speaking speed, facial expressions, and gestures — that can lead to true comprehension. And when more than six people are present in a meeting, then reading those cues – which often operate beneath our conscious awareness – and tracking how each participant is processing your words, becomes nearly impossible.

Because nods and polite smiles from your audience can mask a lack of genuine understanding. And cultural differences can amplify this challenge. 

Traps and differences

In the USA, for instance, speaking up if you have an idea is considered normal. It’s seen as a positive demonstration of initiative. But many Asian countries view such behaviour as rude. They believe you should wait until asked before offering your opinion. Even within Europe, behaviour can vary. When I moved from the Netherlands to work in Sweden, I was struck by how differently my new colleagues expressed and interpreted emotions. At first, I didn’t realise that silence didn’t necessarily mean agreement. Once I understood this, I began actively seeking people’s views before reaching conclusions — something I hadn’t needed to do in the Netherlands. It took time, and a lot of careful listening, to truly understand my new environment.

Long-term

Long-term collaboration within a team can build an almost wordless understanding — what’s sometimes called ‘working in sync’. Like a surgeon and their assistants coordinating seamlessly in an operating room, teams that know each other well can often read each other’s intentions and act without explicit instructions.

But even this harmony carries risks. Such highly attuned groups can close themselves off to outside perspectives and fall into groupthink. Avoiding this means maintaining a conscious balance: staying open to new ideas, even when a team’s internal rhythm is strong.

Because there’s also a hidden trap for those with strong mentalizing skills: they can easily assume that if they understand something, others must too. And this unconscious bias can make it hard to notice when listeners aren’t following along. 

Three practical tips

So how can we best communicate with others? I’d like to offer three practical tips.

1.     Adjust to group size
If there are fewer than six people in a group, then it’s easier to conduct flexible, dynamic conversations. But with six or more people, you should simplify your message and repeat key points to ensure clarity. Never assume everyone fully understands — make sure you confirm that they understand

2. Be mindful of cultural differences
In international settings, cultural backgrounds can shape how people interpret your words. So be clear and direct. And by repeating key points and asking your audience to repeat them back to you, you can be sure to know when you have made your message clear.

3. For specialist teams, prioritize efficient updates
If you’re working with a specialized team – people who understand their field – then regular, concise updates can be more effective than long meetings. Short, well-planned updates can save time and energy and keep everyone on the same page

Good communication means making sure you’ve communicated.