You think it's just a quick message.
Your team reads it as the rule.

It is 10:14 on a Tuesday night. You have one last thought before you can finally let the day go, so you send it. A short message to your team. Nothing urgent. You even add "no rush, tomorrow is fine" at the end, because you are a considerate boss and you mean it. You put the phone down feeling a little lighter. You have no real idea what you just switched on.

Here is what the research now shows. When leaders use their phones for work after hours, it does not stay personal. It sets an unspoken rule the whole team absorbs, a shared sense that being reachable at night is simply what is expected here. And that expectation, more than the workload itself, is what quietly wears people down.

If you are the one sending those messages, this is not a piece designed to make you feel guilty. And if you are the one who flinches when your phone lights up at night, this is not a piece telling you that you are too sensitive. It is a look at a real, measured mechanism that most workplaces run on without ever deciding to, and at what it is costing the people inside it.

What did the study actually find?

In 2025, a research team led by Frederik Hesse at the University of St. Gallen published a large organisational study in the Journal of Occupational and Organizational Psychology with a plain-spoken title: "Always on-line?" It drew on 142 companies and responses from more than 23,000 employees, both managers and the people who work for them. That scale matters. This is not a single office or a lab experiment. It is a pattern visible across an entire economy of workplaces.

The finding is this. The more that leaders across an organisation used their phones for work after hours, the stronger a shared climate of constant connectivity became, defined as employees' collectively held belief that the organisation expects them to stay available and responsive outside working hours. And that climate, in turn, was linked to higher collective emotional exhaustion. The phone habit at the top did not stay at the top. It travelled down as a norm, and the norm arrived as tiredness.

Why does one leader's phone habit change everyone?

Because a message from someone senior is never read purely as information. It is read as evidence. When it lands at 10pm, part of the mind files away a quiet lesson: this is when we work, this is what staying in good standing looks like, this is the speed I am being measured at. You did not issue a policy. You modelled one. And people learn far more from what a leader does at night than from what the handbook says about work-life balance.

This is why the "no rush, tomorrow is fine" at the end rarely lands the way you meant it. The words say one thing. The timestamp says another. Your team has watched enough of these to trust the pattern over the disclaimer. Surveys suggest that around a quarter of employees already respond to work messages after hours as a matter of routine. Most of them were never told to. They simply read the room, and the room was lit by a manager's screen.

Your late-night message is never just a message. It is a memo about what this team believes is required to keep your respect, and everyone reads it, including the people who never reply.

But I never told anyone they had to reply. Doesn't that count?

It counts for less than you would hope, and the study explains why. The damage in the data does not come mainly from the act of answering. It comes from the expectation of being reachable. Once that expectation settles in, it does its work whether or not a single reply is ever sent. People keep half an eye on the phone through dinner. They draft answers in their head on the drive home. They never fully clock off, because clocking off now feels like a small risk.

The researchers describe this climate as something that drains two kinds of resources at once. It eats the personal ones, the energy and unbroken time a person needs to recover from a working day. And it eats the contextual ones, most notably a person's sense of control over their own evenings, and their quiet confidence that they are secure and doing fine. Take enough of both, often enough, and you get exactly what the study measured: exhaustion that belongs to the whole group, not just to the individuals who happen to answer fastest. This is the same machinery behind the feeling described in our piece on why you can't switch off from work, seen this time from the top down.

What if you are the one bracing for the ping?

Then the study is naming something you have probably struggled to justify. The exhaustion you feel is not a sign that you are weak, or bad at boundaries, or somehow less committed than your colleagues. You are living inside a climate that was built, message by message, above your head. The tiredness is a rational response to an environment that keeps a low-grade demand switched on in the background of your life.

That reframing matters, because when the pressure feels invisible people tend to blame themselves for buckling under it. It is worth seeing clearly how much of your bandwidth is already being spent just staying alert. The Mental Bandwidth Calculator on this site is built to make that concrete, to show how much of your capacity is quietly committed before the "real" work even starts. If the constant readiness has tipped into something heavier, the honest look in the piece on manager burnout may sound familiar.

So what actually loosens the grip?

Here the study offers a genuinely useful clue. The exhaustion effect was weaker in organisations with more formalisation, meaning clear and explicit norms rather than rules everyone has to infer from behaviour. Put simply, when a team decides out loud what is actually expected after hours, the guessing stops, and the guessing is a large part of what drains people. Ambiguity is the tax. Clarity is the refund.

In practice that looks unglamorous and works anyway. Saying plainly when a reply is genuinely needed and when it truly is not. Scheduling non-urgent messages to send in the morning, so your own restless 10pm does not become the team's. Above all, a leader visibly switching off, because a team almost never grants itself more permission to rest than it sees the person at the top take. None of this is about caring less. It is about deciding the norm on purpose, instead of letting a phone habit decide it for you. If your own relationship with the work has quietly become the problem you are modelling, the reflection in Still On Your List is a gentle place to notice what you have been carrying, and the Career Alignment Test can show whether the always-on drive is pointing you somewhere you actually want to go.

Where a real conversation comes in

Notice what this research is really putting in front of you. Not another productivity system, and not a lecture about balance. It is a mirror held up to a habit that has consequences you cannot see from inside it, whether you are the person setting the climate or the person living in it. That is a hard thing to look at honestly on your own, because the same drive that keeps you reachable at night is very good at explaining why this time it was necessary.

What tends to help is not advice and not a pep talk. It is a real, two-way conversation with someone whose only job in that hour is to listen and help you think, so the vague sense that "this is not sustainable" turns into a clear picture of what you actually want your evenings, and your team's, to look like. That is a fair description of what good coaching and counselling are for.

If this article read like a description of your own week, that is worth taking seriously, and worth talking through with a person rather than managing quietly for another year.

Common questions about after-hours messages and burnout