How to tell if someone is an expert – from an actual expert

Have you ever listened to a talk by somebody who came across as an expert, only to find that they had no clue after all? Or perhaps you’ve been annoyed by a colleague who explains the obvious in a condescending way. The way expertise is expressed is very similar to how confidence is expressed. And despite the trope of mansplaining, this happens independent of gender, although communicative styles do tend to differ between the genders.

When someone states their thoughts with high confidence, we assume they know what they are talking about and we are inclined to believe them. Often enough, we are correct: there are various indications in the way they talk that reflect their knowledge. However, it’s relatively easy to express certainty in language without having any sort of expertise to back it up. For more than 20 years, I’ve studied how people communicate their thoughts through language – including how they demonstrate expertise and confidence in their discourse.

Experts may know exactly what they cannot be sure about, while non-experts may confidently claim pure nonsense, if they believe in it. Some may even be skilled at claiming nonsense even if they don’t believe in it – this might help their political career or other interests that can be served by misleading people.

Actual expertise is important in a world where misinformation spreads easily. Here are five questions to ask yourself to determine whether the person you’re listening to is an expert, or just a confident speaker:

Consider their background, their possible motivation, their skills and goals in the present conversation. People may have true expertise and knowledge in areas you wouldn’t expect. But seeing no relation between what you know about this person and their proclaimed expertise is an indication that they’re just overconfident in a topic they actually know little about.

In research, actual expertise can be identified by objective measures such as facts about a person’s life history, or performance assessments. For instance, experts differ from novices in memory as well as perception and categorisation of complex facts. In daily life, awareness of someone’s background can help you treat their statements with appropriate caution.

People differ in their communicative styles. Some tend to talk over others as a habit, needing to dominate a conversation. Others listen more, offering opinions and views only when they’re well-founded.

In a medical setting, an attentive style – one that prioritises listening over talking – can lead to better collaboration between physicians and nurses and improve the quality of care for the patient.

Sometimes it is wise to listen to the quieter voices: they might have more value to add than non-stop talkers.

Sweeping statements are easy to make. While experts know more details and will be ready to provide them, people without true knowledge have to stay on a superficial level. They might repeat the same general message over again, unable to elaborate. This presents another problem: If a message is repeated often enough, we will eventually believe it – that’s only natural. When it comes to COVID-19, research shows people believe repeated false information, especially about less known aspects.

Events that we have not observed with our own eyes, that cannot be repeated in a scientific experiment, that happened long ago in the past or in the future – all of these naturally come with a certain amount of uncertainty. An expert will adequately acknowledge the limits to certainty. Their statements will contain uncertainty markers (words such as “maybe” or “could”) where appropriate.

Here, a crucial difference is that between “I am uncertain” and “It is uncertain”. A non-expert simply doesn’t know the available facts. But an expert knows whatever can be known about the matter at hand. In some cases, this goes as far as stating explicitly what the likelihood of a certain event is. Climate experts, for instance, will not be able to predict extreme weather events with certainty, beyond what immediate weather forecasts can provide. However, they can demonstrate how the occurrence of such events has increased in the past, and based on this they can provide the statistical likelihood of events such as flooding for the future.

Consider the difference between automatic route navigation systems (such as Google Maps) and the kind of directions you would get from a friend. The friend would be able to give you just the information you need, providing more details at tricky decision points, but skipping over those parts of the route that they know you’re already familiar with. Automatic systems are unable to do that. They’re not “experts” – they’re simply pulling information from a database, without actual insight or intelligence, using the same phrases over and over again.

True experts use concepts and terminology in their field (jargon) flexibly and with ease – and they are typically able to adjust their communication to accommodate the specific needs of their audience.