The 4-word ‘hack’ confident people use to get others to agree with them—it makes you ‘influential,’ expert says

Want to win more arguments? Use this simple four-word “hack,” says an influence expert: Keep your explanation brief.

The more bullet points you add to your argument, the less persuasive it becomes, says Niro Sivanathan, an organizational behavior professor at London Business School.

“Most people make the forecasting error that in order to win people over, you need to get them lots of data,” Sivanthan tells CNBC Make It. “Oftentimes, things fail not in content, but delivery.”

It’s called the dilution effect: Your strongest claims get watered down the weaker ones. People listening will walk away remembering the average persuasiveness of each point you make, rather than your single most convincing argument, Sivanthan explains.

If you’re trying to convince your friend that New York is the best city in the world, for example, you might cite the pizza, Broadway shows, public transit and Times Square. Depending on your audience, some of those points will be more persuasive than the others, and you’re better off only using the ones most likely to win your friend over.

“Less is more,” says Sivanthan. “If you have just one key argument, be confident and put that on the table, rather than feeling the need to list many others.”

The inverse of this strategy also works, according to Sivanthan’s research. After watching drug commercials, consumers were more likely to view a drug favorably when the companies listed a moderate side effect right after a severe one, his 2017 study found.

Using the dilution effect to make your arguments more persuasive can be a “very easy fix,” Sivanthan says. It can help you land a job, shorten your presentations and make your dinner table debates more cordial.

It does require self-control. Once you’ve laid out your core argument, you have to be comfortable letting it hover in silence until the other person is ready to respond. Otherwise, you’ll find yourself inadvertently jumping in again with additional weaker…