What the research supports and what it oversells

You will be able to separate reasonable claims about emotional intelligence from overstated ones and ask the right questions of any study.

A week after the test brochures, Hui Min's director forwards a post to the HR team. It says that emotional intelligence explains more than half of success at work, that people with high scores earn far more, and that the company should train it into every manager. There is a chart, a confident tone and no link to a study. The director's note reads: "Can we do something like this?"

You will see posts like this every month. Some are partly right, and many stretch a modest finding into a big promise. This lesson gives you a way to tell which is which without needing a statistics degree.

The debate researchers are still having

The central argument in the research is about what emotional intelligence adds. Psychologists already have good measures of general intelligence and of the main personality traits, such as conscientiousness, agreeableness and emotional stability. These measures predict a fair amount about how people do at work. The question is whether an emotional intelligence score tells you anything extra once you know those.

It depends heavily on the type of test, which is why lesson 1.2, Why different emotional intelligence tests disagree, came first. Self-report and mixed-model scores overlap a lot with personality. So some of what they seem to predict is really personality. Ability scores overlap less, but their links to everyday outcomes are also weaker and less consistent. How much is left once you account for personality and intelligence is still argued over in the journals. A post that skips that argument is selling you something.

What the job performance research looks like

Studies that link emotional intelligence to job performance usually find relationships that are modest. They are real in many studies, but they are much smaller than the popular claims suggest, and they move around.

Two things make them move. The first is the test used, for the reasons above. The second is the job itself. A meta-analysis by Dana Joseph and Daniel Newman, published in 2010, found that the link was stronger in jobs that demand a lot of emotional work, such as customer service and sales, where you have to manage your own feelings and other people's all day. In jobs with less of that demand, the link was weaker. That makes intuitive sense. Reading a frustrated customer well matters more on a service counter at Changi Airport than in a role spent mostly on spreadsheets.

So when someone says emotional intelligence predicts performance, the fair reply is: measured how, and in which jobs?

Specific skills have their own evidence

You get further by dropping the single score and looking at individual skills. Several have been studied directly, often more carefully than the umbrella term.

Reappraisal, changing how you interpret an event so that your feeling about it changes, has a large body of work behind it, much of it from James Gross and colleagues at Stanford. Putting feelings into words, sometimes called affect labelling, has been studied by Matthew Lieberman's lab at UCLA. You will meet both in modules 2 and 3. None of this work depends on settling what emotional intelligence is. Each study asks a narrower question: if people do this one thing, does a particular outcome change?

That is why this course is built around skills. You can argue for years about the right definition of emotional intelligence. You can test whether pausing before you reply to an angry email makes the next day go better in a week.

Three questions for any claim

When you meet a claim about emotional intelligence, ask three things.

First, which measure? Was it an ability test, a self-report questionnaire or a mixed-model tool? If the post does not say, that is already a warning.

Second, compared with what? A finding that high scorers do better means little if they were also more experienced, more senior or higher on conscientiousness. The better studies check whether emotional intelligence predicts anything after taking those into account.

Third, how large was the difference? "Linked to" can mean a strong relationship or a barely detectable one. Popular articles rarely tell you which. If the source will not say how big the effect was, assume it was small until you see otherwise.

Rewriting a claim so it is fair

Here is how Hui Min handled the director's post. The original said emotional intelligence explains more than half of success at work. She could not find a published study behind that figure, so she dropped it entirely. The post said high scorers earn more, but gave no measure and no comparison, so she could not support that either.

Her rewrite read: "Studies link some emotional skills to job performance, more clearly in roles with heavy emotional demands such as service and sales. The links are usually modest and depend on how the skills are measured. Specific skills such as reappraisal have their own evidence and can be practised."

It is less exciting than the original. She could defend every word of it to a sceptical finance director, though, and it still gave her a reason to build training around specific skills. In the activity below you find a claim of your own and give it the same treatment. Keep only what the evidence behind it could carry.

Find one article or post that makes a claim about emotional intelligence and rewrite the claim so it says only what the evidence behind it could support.

Course

• Emotional intelligence and difficult conversations