In trust communications, sometimes the most effective message is the one you don’t send.

WhatsApp’s latest global campaign boldly informed its users: “Not even WhatsApp can see your personal messages.” The notification, part of the messaging service’s largest-ever marketing push, promises 3 billion users that their chats remain invisible even to the platform itself. Yet according to psychology and behavioural science this confident assertion of privacy may backfire.

The campaign represents a high-stakes gamble in trust communications. By loudly proclaiming its encryption credentials, WhatsApp hopes to differentiate itself from less secure rivals and shore up trust amid growing privacy concerns. Trust in brands relies on three pillars: competence, integrity, and benevolence and WhatsApp’s campaign ticks these boxes theoretically: highlighting technical prowess (competence), transparent assurances (integrity), and user-first priorities (benevolence).

But behavioural science suggests a more complex reality. One of the ways we assess integrity is whether a brand’s observed actions match its stated priorities. By using what is arguably an invasion of a person’s privacy (directly messaging them, unrequested) to talk about how they don’t invade privacy, perceptions of WhatsApps’ integrity may well suffer.

Alongside this, research at Carnegie Mellon found that when people are reminded about privacy, even positively, they become more anxious, not less. This “privacy salience” effect means that highlighting confidentiality can inadvertently raise alarm bells. Much like a dentist’s cheerful “this won’t hurt a bit” often does little to calm nerves, users are now gripping their phones, suddenly wondering why the platform felt compelled to make such assurances.

How the message is received depends largely on existing trust levels. Users with high trust may genuinely feel reassured, particularly those unfamiliar with encryption technicalities. They read WhatsApp’s promise and think: “Good to know my conversations are safe.” For them, the campaign successfully demonstrates both technical competence and corporate integrity. However, we would assume this pre-existing high-trust audience is not the main target of this campaign.

Low-trust users react differently. Privacy-conscious consumers and those who remember past controversies—such as the 2021 data-sharing policy changes that drove users to Signal—hear alarm bells. They ask: “Why are they telling me this now? What’s prompted this defensive messaging?” Such users likely understand that while your message content may be encrypted, metadata (who you contact, when, how often) remains visible and valuable. They may feel like the message they are being served is misleading at best.

This divergence illustrates a fundamental challenge in trust communications for organisations. In an age where concerns about privacy are high and trust is much sought after, brands must walk a tightrope – making the right claims without appearing to “protest too much” or unwittingly drawing attention to sensitive issues.

Looking at another sector, we recently worked with a leading airline that wanted to reassure passengers and staff about the safety of their planes. The one thing we told them not to do was loudly proclaim how safe their planes were, causing people to immediately assume there was something to worry about.

For comms professionals, WhatsApp’s campaign offers valuable lessons:

1. Know how hard to push – push too hard and risk triggering the very suspicion you seek to dispel.
2. Understand your audience – trust-building calibrated for one audience may have the opposite effect on another.
3. Align your words and actions – trust is quickly undermined when these are perceived as out of sync.
4. Channel matters – we are receptive to different forms of messaging on different channels; what works in one place may not work in another.

WhatsApp has chosen the loudspeaker approach in an age of data paranoia. Whether this strategy succeeds will depend not on the frequency of privacy assurances, but on the platform’s ability to highlight them in the right places at the right times, while honouring them consistently.

About the Authors:

This blog was co-authored by Sam Ward, Strategy Associate Director at MHP Group, and Dr Keith O’Brien, behavioural scientist and consulting director at Influence at Work.

Dr Keith O’Brien is a behavioural scientist and Consulting Director at Influence at Work. He is a leading expert in applying psychology to understand and change consumer behaviour in digital contexts.

Sam Munteanu-Ward is Strategy Associate Director at MHP Group, where he specialises in strategic communications and brand development for technology and finance clients.