Coherent Essays Contain Persuasive Messages

Imagine two people try to convince you to buy their respective brands of kitchen products. The first representative gives you 10 reasons to buy her brand and the second representative only gives you 1 reason. So far, the first person seems more persuasive. After all, aren’t 10 reasons better than 1?

But what if the first person gives 5 compelling reasons to buy her brand and the other 5 reasons are obviously filler? What if all 10 reasons are silly and the second representative’s only argument is actually really compelling?

Clearly, the question of “quality vs. quantity” in the persuasion game gets complicated fast. Luckily, psychological research gives us insight into how persuaded people are by long and short messages that are strong or weak.

“Strength in Length”: Are More Arguments Always Better?

One early study presented people with a simulated court trial. The participants in the study pretended to be jurors in the case, and they listened to the arguments from the prosecution and the defense. The materials were set up so that one side had more arguments than the other. Specifically, one side would give one argument and the other would give seven. Not surprisingly, in this scenario, participants’ verdicts came down on whichever side provided more arguments.

One question researchers have asked, though, is: do more arguments make a more persuasive message even when those arguments are weak? In other words, it makes sense that 10 compelling arguments would be more persuasive than only 1 compelling argument, but it’s not clear whether having 10 really stupid arguments is any more persuasive than having just 1 stupid argument.

More Reasons Produce More Persuasion When People Aren’t Thinking Much

You can think of the “Longer is Stronger” rule as a trick people can use when they don’t want to actually read or listen to the whole message. It turns out that having more reasons is still more persuasive, even if those reasons aren’t any good, when people aren’t paying close attention to the message, As Richard Petty and John Cacioppo wrote:

If people are unmotivated or are unable to think about the message…they might invoke the simple but reasonable decision rule, “the more arguments the better.”

To test whether people really do this, one study gave people an essay containing either three reasons to adopt a new policy or nine reasons to do so. For some people, all of the reasons provided in the essay were strong, compelling reasons, but for everyone else, all of the reasons were really weak.

For people who didn’t care about the policy (so they weren’t too interested in dissecting the arguments), they were more persuaded when they saw nine reasons than when they saw three. It didn’t even matter whether those reasons were strong or weak.

Another study showed similar results. When people weren’t really paying close attention to an article, they changed their opinions more if the article was relatively long, compared to when it was shorter. Once again, the quality of the article didn’t matter—just the length.

What About When People Are Thinking?

Okay, so you have a captive audience, and they’re willing to think deeply about your persuasive arguments. Should you still strive to craft a lot of arguments regardless of their quality?

Under these circumstances, the research suggests that you should make sure your arguments are good first and then worry about how many you have. In the two studies I mentioned above, when the conditions were flipped and people were in a position to really read and consider the persuasive essays, they were more persuaded when the essays had strong arguments than when they had weak ones.

It’s possible, though, that having more good arguments can still be better than having only a few good arguments. In other words, if you know people are paying attention, you may not want to completely disregard the length of your message. In bothstudies, there’s a tendency for messages with many compelling arguments to outperform those with only a few compelling arguments (when people are paying attention).

When Longer Messages Can Backfire

Overall, it seems like it wouldn’t hurt to just make sure you have longer messages. It’ll appeal to people who aren’t paying close attention, and it can still be impressive to people who are paying attention.

Still, you need to consider the inherent strength of the claims you’re making. There’s a trend in one of the studies I’ve reviewed here where having more arguments can produce less persuasion. This is the case when (a) all of the arguments are actually weak and (b) the audience feels compelled to really process what the person has to say. You can imagine someone in this position thinking, “Wow–these aren’t persuasive at all…and there are so many of them!”

Also, other research has shown that adding weak arguments to strong arguments can water down the impact of a persuasive message. Even though a message with nine compelling reasons is better than one with just three, adding weak reasons to a message that has nine compelling ones reduces its persuasiveness.

Finally, some have suggested that messages can lose their impact if they get too long, regardless of how good its points are. If a message drags on, people can tune out, especially if the arguments become really repetitive.

Was This Article Long Enough For You?

So, as with most things, the answer to the question “Is it more persuasive to have a lot of arguments?” is: “it depends.”

When you have a lot of “objectively” persuasive reasons that you can give people, then it seems like it’s better to present all of them For people who aren’t ready to invest the time it takes to process your message, the sheer number of arguments will be persuasive. For people who are ready to think about your message, the quality (and number) will be persuasive.

If you know that you don’t have too many compelling arguments in your arsenal, then you need to think about how closely people will be paying attention. If you know that your audience isn’t likely to give your message too much thought, then pile on the vacuous arguments! If your message will be held to scrutiny, then stick with your more compelling arguments, even if there are only a few.


If you’re interested in the psychology of persuasion, check out my new online psychology course: Master Persuasion Psychology, available now. Use this link or the coupon code “blog29” to get a huge deal on the enrollment cost.


Categories Blog, Persuasion Science BlogTags arguments, attitudes, elaboration, opinions, peripheral cues, persuasion, social influence

One of things many undergraduate students I have worked with over the years have always battled with is understanding the difference between an essay that makes an argument, and an essay that has useful information in it that is not tied together around a central thread or point. In my former role as the coordinator of a university writing centre, I spent a great deal of time thinking about how to help students understand and address this struggle through writing workshops and tutorials, and in my work with their lecturers and tutors.

Getting your head around what an argument is, and how to craft and make substantive and coherent arguments, is key to succeeding at your higher education studies and beyond, and not just in the humanities and social sciences. Although they may do it in different ways and in different forms, all fields make and defend arguments for and against things: this design for a footbridge rather than that one for this community; this method for building a hydrology model rather than that one in this project site; this theory of neoliberal capitalism and its effects on modern society and not a different one; and so on.


The argument is the answer to the ‘So what?’ question you don’t want your readers to ask at the end of your essay. It is the ‘golden thread’ if you like, that takes the strands of your argument and pulls them into a defined shape to substantiate and develop the central claim your essay wants to make. This is often called ‘the thesis statement’. It needs to be clearly made, often in the introductory part of your writing, so that your reader knows what it is that is helping you to select and organise the parts of your essay or paper that will follow. What follows the introduction will be a connected selection of sub-claims, supported by relevant evidence, that further develop and substantiate the central claim, and all of these sub-claims must make up this golden thread – they need to connect, in a logical and coherent order, to create an argument that is persuasive and makes sense.


You could think of these sub-claims, and the evidence you have selected from literature or empirical data, or both, as strands of coloured wool. On their own, side-by-side, they just make up a collection of strands of coloured wool. Without a purpose or aim to draw them together into a blanket or a scarf or similar, they are just pretty strands of wool. They need a knitter and the knitter needs a pattern to follow. In undergraduate and early postgraduate studies, where students are completing coursework, they are given their ‘knitting patterns’ in the form of task questions and instructions to respond to. Later on, in independent research, students need to design their own patterns, or research tasks.

Students, as the knitters, will read (or devise) the task, decide on what research needs to be done to generate the information needed to respond appropriately to the task, and using their prior learning as well as the thinking, reading and writing practice they have had thus far, they will ideally weave or knit the information together to create something new, that represents (hopefully in their own creative way) the pattern they were asked to follow. They will create new knowledge from existing knowledge, even in a small way, by taking a position on an issue and advancing a substantiated argument. Without the argument to tie the strands together into a pattern, the essay will likely end up looking a bit like the picture above – a collection of paragraphs, each with their own point, but together not quite managing to create something coherent or sensible. The essay may well leave the reader wondering: ‘So what? What is the point of all of this?’

A tool I recently learnt on a writing retreat has really helped me to create a define my own ‘pattern’ for my writing, and is helping me to make sure that I am actually knitting together arguments in my papers that make sense, and are properly substantiated. Taken from a book called The Craft of Research, the tool helps writers to plot out the golden thread by asking them to think carefully about the main claim, the sub-claims, the reasons for those claims, and the evidence needed to substantiate them. Claims and evidence are probably quite obvious – of course we need both of these elements to write a paper worth its salt. But what of reasons? According to the authors, reasons are important because they outline the logic of the argument you want to make. I have learned, using this tool, that I am quite good at generating many reasons for the research I want to write about, but I am less adept at pinning down my claims. This tool has been helping me to work on this.

This (below) is my version of the tool in action: an argument for a paper I am working on plotted out in my research journal on stickies. Following the retreat facilitator’s advice, I use stickies to avoid writing long-winded claims and reasons. This is not the plan for your paper, this is the plan for your argument, and you need to be able to identify and state your claims, reasons, and related evidence fairly concisely. If it takes you 7 or 8 stickies to state one claim, you have some more thinking and refining to do before you are ready to plot out your paper and knit your strands together.

I start with my main claim, and then identify any sub-claims that are part of that. I then write out the reasons for the claims I am making, and follow with the evidence I either have, or need to have, to support these claims. The orange stickies at the end contain my ‘take-home message’ or the answer to the ‘So what?’ question (which will be part of my conclusion) as well as the limitations on the argument I want to make. Not every paper will include limitations, but all papers need to have claims, reasons, evidence, and a clear answer to the ‘So what?’ question. All papers we write, whether as undergrads, postgrads or professionals, need to have a point – and the point is the argument, and the way in which we are weaving that golden thread through the writing to create something new from all the strands of research, reading and thinking we have been doing.


If you are a writing teacher or tutor: consider using or adapting a tool like this to help students you work with understand the link between the research they are doing and the information they are gathering, and the ways in which this information and research need to be pulled together selectively around a central argument that knits all the paragraphs or parts together into a coherent, persuasive whole.

If you are a writer: try this tool out, and look for others that can help you to make clearer the ways in which your arguments are constructed and crafted, to ensure that your own writing is a clear, persuasive and makes as much sense as possible.

Reference: Booth, C., Colomb, G. and Williams, J. (Eds) 2003. The Craft of Research. Chicago: University of Chicago Press.

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