RESEARCH NOTES #4

Complex or simple comms? Actually, there's space for both

Alan might be capable of more processing capacity than you think...

One of the things I very often find myself saying to the leaders I coach is, ‘think about who you’re communicating to… and think about what you want to happen’.

One of the things I do not say very often is, ‘make your content more technical/complex/ sophisticated’. In fact, it’s often the reverse; make it more accessible, easy to engage with and digest (and remember). One thing I reflect on time and time again is that inspirational leaders do not talk like technocrats. They’re above acronyms and buzzwords and all the little ‘tells’ that some people use to assert competence or expertise (but which often signals the opposite).

Jamie Dimon, arguably the most successful banker of his generation, recently replied to the whole trade wars farrago (and pressure from Donald Trump) by simply asserting, “I’m not really a tariffs guy”. Me neither, Jamie. Me neither.

Hanging over these first four paragraphs is (you might have felt it coming) a great big handbrake pivot of the whole ‘simplify is best’ vehicle… because sometimes, it’s not.

I get speakers and their comms teams going into debate about whether rhetorical flourishes and complex phrasing make a speech better or whether simple, plain language is more effective.

So we tasked our research guru with a dive into the library stacks to find out: what’s the evidence for either side?

The empirical literature suggests that there is no universal winner. Language complexity interacts with audience characteristics, comms goals such as persuasion or credibility, and also the structure and delivery of the speech.

Two explanatory mechanisms come up often in the research. First, processing fluency. This refers to the ease with which listeners cognitively process language. The second relates to elaboration and credibility, since complexity can sometimes increase perceived competence or provide richer arguments that persuade motivated or expert listeners. These two mechanisms help explain why simplicity and complexity each have advantages in particular circumstances.

Processing fluency and the advantages of simple language

A large body of cognitive psychology shows that when stimuli are easier to process, people tend to judge them more positively. Classic experiments manipulating the ease of conceptual and perceptual understanding demonstrate that fluent stimuli are judged as more pleasant, more truthful and more persuasive in many situations. So therefore, the processing fluency effect helps explain why plain language often improves immediate audience reactions. Listeners understand faster, feel more comfortable and are more likely to accept simple claims without resistance.

Applied studies reinforce these findings in communication settings. Research in health communication and public guidance repeatedly shows that plain language increases comprehension, recall and self-reported usability for the public they’re aimed at. Particularly when literacy or subject knowledge might be lower, for example with diverse groups in populations. Public health agencies and non academic sources (‘grey’ literature) recommend plain language versions of technical reports in order to expand reach and reduce misunderstandings. So, the evidence here is for the clear benefits for comprehension and accessibility.

When complexity becomes useful

Despite the advantages of simplicity, complexity is not inherently negative. In political communication and persuasion (one might argue, not every current leader fully espouses this view), information-rich and complex messages can increase persuasion, especially if audiences are motivated to accept elaborate or nuanced argument, or when complexity functions as a signal of expertise.

Experimental and naturalistic studies in persuasion show that linguistic features increasing information density may persuade highly engaged or knowledgeable listeners because they offer more substantive content to evaluate.

In other words, smart audiences might favour smart (and complex) arguments and structures.

In addition, political communication research shows that media coverage often amplifies information-dense or provocative statements, which means that those speakers who want to attract media attention may intentionally use denser phrasing – and the same applies to commercial settings.

Empirical investigations of political texts and official speeches show mixed patterns rather than a single, directional effect. Studies of central bank speeches, for example, reveal that readability levels fluctuate depending on intended audiences. Simpler phrasing improves public comprehension, yet technical complexity is sometimes retained to address expert stakeholders or to express uncertainty more precisely. Students of US central bank speeches may remember the gnomic musings of Alan Greenspan; when I was a financial reporter, we pored over their implications for days. Irrational exuberance, anyone?

Similarly, research on political information acquisition shows that complexity influences how audiences absorb information. Higher complexity can reduce learning among casual audiences but can support deeper understanding among highly motivated individuals who are willing to engage with harder material.

‘Good’ speeches and audience engagement

Quality and engagement are multidimensional outcomes. The effect of simplicity versus complexity depends on which outcome is being measured. If ‘effective’ is defined in terms of comprehension, recall, or immediate liking, simple language consistently outperforms more complex phrasing. Audiences tend to prefer concrete examples and straightforward structure. If quality is defined in terms of sophistication or the ability to convey nuanced arguments to specialist audiences, complexity can become an asset.

Engagement similarly exists through multiple layers. Surface-level engagement, including attention, liking, or initial emotional resonance, is generally stronger with clear, accessible language. Rhetorical devices such as repetition and clear signposting further enhance this effect. Deeper engagement, including debate, reflection and subsequent seeking of more information, may be stimulated by novel or challenging language when audiences are highly motivated. Studies across political rhetoric and marketing communication support this dual view of engagement, showing that accessibility increases immediate connection – while complexity can encourage longer term cognitive involvement for invested listeners.

Shaping understanding

Going back to 1) who is your audience, and 20 what do you want to happen, it’s clear that the outcome goal defines how you use language.

When the objective might just be comprehension, trust building or audience guidance, clarity should be prioritised. But complex ideas can be made more accessible through careful structuring such as clear transitions, summaries, illustrative examples, and the use of anecdote and analogy to ‘show’ rather than ‘tell’. This helps preserve informational richness while maintaining ease of processing. Guides for communicators in government or public agency literature emphasise structure as a key contributor to effective engagement.

And it’s not just the words you use. The content is augmented by some non-linguistic fluency cues.

Factors such as pacing, pausing and visual clarity interact with linguistic complexity. A well paced delivery can moderate the disfluency associated with complex phrasing. Experimental work on fluency indicates that these cues shape responses in ways that complement linguistic features.

Conclusion

There is no universal rule that simpler or more complex speeches are always better. Plain language yields clear advantages for comprehension, recall and general audience engagement, particularly when communicating with broad or less specialised audiences. Research in health communication, public policy and psychology consistently supports these benefits. Complexity, however, plays an important role when communicating with expert audiences, when attempting to convey detailed evidence or when seeking to signal competence and expertise. In political and specialist communication, complexity can increase persuasive power and attract deeper cognitive engagement when audiences are motivated to elaborate.

The most thoughtful, most effective communicators tailor language complexity to the audience, the goals of the speech and the context of delivery. You might need simplicity in a certain part of your communication it might need to be more complex elsewhere, but understanding and helping audiences embrace complexity means a balanced approach that combines the benefits of both styles.

Selected references (academic + grey literature cited above)

Reber, R., Winkielman, P., & Schwarz, N. (1998). Effects of perceptual fluency on affective judgments. Psychological Science, 9(1), 45–48.

Ta, V. P., Boyd, R. L., Seraj, S., Keller, A., Griffith, C., Loggarakis, A., & Medema, L. (2021). An inclusive, real‑world investigation of persuasion in language and verbal behavior. Journal of Computational Social Science, 5, 883–903.

Tolochko, P., Song, H., & Boomgaarden, H. (2019). “That looks hard!”: Effects of objective and perceived textual complexity on factual and structural political knowledge. Political Communication, 36(4), 609–628

Bjerkander, L., & Glas, A. (2024). Talking in a language that everyone can understand? Clarity of speeches by the ECB Executive Board. Journal of International Money and Finance, 149, Article 103200.

Langaufová, A., Beharková, N., Friessová, T., Pokorná, A., Dolanová, D., Vrbová, T., & Burilová, P. (2025). Processes for developing plain language versions of guidelines recommendations: A scoping review. Journal of Evaluation in Clinical Practice.