A Little Idea

One Little Idea: avoid periods when possible

“God is in the details”, said Mies Van Der Roh. But did he end that statement with a period?

When I examined the bold claim that machine learning outperformed human copywriters, I noticed instantly that this competition was flawed.


Because the human in this competition ended his or her headline with a period:

“Access cash from the equity in your home.”

This means that the machine had an unfair advantage.

Here is a small piece of advice for you… 

Don’t Use a Period in Your Headlines or Messages

Why not?

Because periods make people stop reading – that’s the reason usually given, and it’s true.

But for two other reasons – a period after a headline reduces comprehension and it can impart hostility.

You’ll often see a quote ending in a period, but a quote is not a headline. A quote is self-contained; it is its own content. Whereas a headline exists only in relation to something else.

Headlines are everywhere – I define them as simply, “the most visible phrase in a given user interface, digital or not”. Examples include the title of a blog post, an email subject line, or the classic example, an ad.

Data scientist Daniel Starch established that periods didn’t work well in headlines by doing analytics on a vast data set – 5 million direct mail advertisements.

In 1930. We figured this out long ago.

Speaking of History

Sidebar – in From Dawn to Decadence, Jacques Barzun established beyond any reasonable doubt that the lifestyle we enjoy today was pioneered in the 1880s.

In a very real sense, you and I live an 1880’s lifestyle: separate residential and commercial zones, mass public transport, ubiquitous electricity, indoor plumbing, networked communications/news, elevators for multi-story building use, mass office work, knowledge workers, urban anonymity/angst, etcetera.

Of course, that’s been reshaped a little by mass automobiles, airplanes, the labor movement, the ’60s, and other technological and cultural novelties. But not much. Even the Internet culture has only slightly modified our basic 1880’s lifestyle. Interestingly, it has done so with respect to the period, which I address down below.

Anyway, if we’re living in the 1880s, it should come as no surprise that much of what we know about modern digital marketing was discovered in the 1920s.

To bring it back around, we have known about the period a while.

But it wasn’t until the 1970’s that we started to figure out why the period doesn’t work in headlines. David Ogilvy commissioned a research study found that it had to do with – counterintuitively – comprehension levels. 

When you encounter a headline with a period, you assume it stands on its own two feet. So you try to reexamine it until it makes sense. But it might not make sense, not until you read the rest of the content it goes with – that’s how some headlines work (eg “curiosity headlines”).

So with the caveat that all rules are made to be broken, here’s a slightly bigger but still small idea: be very skeptical of hiring a marketer who uses periods in their headlines – and in their chat/messaging communications with you.

And not just because of marketing concerns but because of emotional intelligence concerns: periods can be hostile.

Linguistics Has an Opinion 

Over the past 12 years, multiple scientific, peer-reviewed studies1 have been published establishing the hostility and rudeness of using periods in messaging.

Of course, in a multi-sentence message, they are needed for clarity. But they are not needed to end a paragraph and are certainly not needed in single or fractional sentence messages.

In a 2016 New York Times interview, linguist and author David Crystal, has come right and said it – the period is now just a harsh emoticon:

“The period now has an emotional charge and has become an emoticon of sorts. In the 1990s the internet created an ethos of linguistic free love where breaking the rules was encouraged and punctuation was one of the ways this could be done”

I can attest to the historical veracity of this statement.

And it’s not just hostile, it stops the flow of interaction, just as advertising researchers discovered for periods after headlines.

Consider the following:

Well, no further thoughts on the subject


Well, no further thoughts on the subject.

The respondent to the latter message is somehow less invited to respond. If they do respond, more effort is required. A justification is required.

To this point, another linguist named Mark Liberman has remarked in a New Republic interview:

“In the world of texting and IMing … the default is to end just by stopping, with no punctuation mark at all … In that situation, choosing to add a period also adds meaning because the reader(s) need to figure out why you did it. And what they infer, plausibly enough, is something like ‘This is final, this is the end of the discussion or at least the end of what I have to contribute to it.’”

I think that’s a good note to end this letter on.. but let me know if you have further thoughts on the subject




1 Here are direct links to three peer-reviewed studies on the period https://www.sciencedirect.com/science/article/pii/S0747563215302181https://www.sciencedirect.com/science/article/pii/S0747563217306192, https://www.researchgate.net/publication/258153166_Text_Messaging_and_IM_Linguistic_Comparison_of_American_College_Data

Also, the Guardian’s Joel Golby published an amusing analysis: https://www.theguardian.com/technology/shortcuts/2015/dec/09/science-has-spoken-ending-a-text-with-a-full-stop-makes-you-a-monster