When Negotiating, Selling or Just Persuading, Quality Over Quantity

Niro Sivanathan is an Associate Professor of Organizational Behavior at London Business School, who teaches Negotiations, Influence and Decision-Making.  His psychological insights can help all of us be better negotiators, influencers and decision makers.  In this blog, I let Niro’s words do most of the talking.

Avoid Irrelevant Points

Niro writes:

Diagnostic information is information of relevance to the evaluation that is needed. Non-diagnostic information is information that is irrelevant or inconsequential to that evaluation. And when both categories of information are mixed, dilution occurs.”

In summary, when we stray from our central argument, whether we want to add background information or share something interesting, we weaken our argument.  Psychologically speaking, the irrelevant information (non-diagnostic information in Niro’s quote) does not help persuade the other person, it just makes it more difficult for them to understand and thus to be persuaded.  Politicians have known this for years as expressed in the political proverb:

If you can’t convince them, confuse them.

And its contrapositive:

If you don’t confuse them, then you can convince them.

Quality Matters More Than Quantity

When we are persuading, we all think that adding further points will help our position.  Instead, adding more, but weaker, arguments worsens our position:

The psychological explanation for this is one of averaging. In this model, we take in information and those pieces of information are afforded a weight or score. And our minds do not add those pieces of information, but rather, average them out. So when you introduce irrelevant, or even weak arguments, those weak arguments reduce the weight of your overall argument.

In short, if we have three “A” negotiating points, adding three “C” negotiating points does not make our argument even stronger (three “A’s” plus three “C’s” is greater than three “A’s”) .  Instead, it means that the merit of our argument is now at the “B” level, not the “A” level.  Fewer strong arguments are far better than many average or weak arguments.

Niro again:

The take-away for communicators is to focus on quality over quantity.  You cannot increase the quality of an argument by simply increasing the quantity of your argument. The next time you want to speak up in a meeting it is important to note that the delivery of your message is every bit as important as the content. Stick to strong arguments.  Because your arguments don’t add up, in the minds of the receiver, they average out.


When negotiating, selling or persuading, keep it short and simple:

  1. Stick to relevant information
  2. Only communicate the strongest arguments

“If you pile on too many different reasons to support your case, it can make your audience defensive – and cause them to reject your entire argument based on its least compelling points. Instead of diluting your argument, lead with a few of your strongest points.” Adam Grant


About David Shedd

David has been a President - CEO - COO of an up to $350M group of manufacturing, distribution, specialty retail and services companies, having led 22 different businesses from turnarounds to start-ups to fast growth companies.
This entry was posted in Business Acumen, Communication, Personal Success and tagged , , , . Bookmark the permalink.

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