Fighting about nothing

Some arguments are genuinely about something. A substantial proportion are not, and identifying which is which prevents a great deal of unnecessary effort.

The ordinary causes

Sleep. The most underrated variable in relationship conflict.

Experimental work on sleep restriction consistently finds effects on emotion regulation, hostility, and the accuracy with which people read others' expressions.

Studies of couples have found that nights of poorer sleep predict more conflict the following day, and that the effect operates in both directions.

Which means a proportion of arguments are the direct product of a bad night and would not have occurred otherwise.

Hunger. Less well established than the popular version suggests, and there is reasonable evidence for effects of low blood glucose on self-control and irritability.

The everyday version — that arguments before dinner go differently from arguments after it — is worth acting on regardless of the mechanism.

Stress from elsewhere. Well documented as spillover. Difficulty at work reliably predicts more conflict at home, and the conflict is generally about something domestic.

Illness, pain and hormonal variation, all of which affect irritability and none of which are usually named at the time.

Accumulated small friction. Where nothing has been raised for a while, the next available subject carries the accumulated charge.

Recognising it

The diagnostic is proportion.

Where the intensity substantially exceeds what the subject would warrant, the subject is not the cause.

Also useful: whether the same event on a different day would have produced any reaction at all. If not, the day is doing the work.

What to do about it

Name the state rather than the subject. "I'm exhausted and I'm going to be unreasonable about anything for the next hour" is one of the more useful sentences available in a relationship.

It is honest, it requires nothing from the other person, and it prevents an argument from being treated as a data point about the relationship.

Defer anything substantive. Decisions and difficult conversations are worse when made in this state, reliably.

Fix the input. Which is unromantic and effective: eat something, sleep, deal with the work problem.

Do not analyse it afterwards. Post-mortems of arguments that were caused by tiredness tend to invent a subject, and the invented subject then becomes real.

The couple-level version

Some structural arrangements reduce the frequency.

Protecting sleep, which frequently means addressing something specific — a snoring partner, a child, different schedules, screens.

Separate bedrooms are worth mentioning here, since the arrangement carries a stigma that the sleep research does not support. Couples who sleep separately for sleep reasons frequently report improvements in both sleep and relationship quality.

Avoiding significant conversations in the last hour of the day.

Building in a transition after work rather than arriving directly into domestic demands.

What this does not cover

The important limit.

Attributing every conflict to tiredness is a way of never addressing anything.

The distinguishing feature is recurrence. An argument about the dishwasher on a bad Tuesday is probably about Tuesday. The same argument every fortnight for two years is about the dishwasher, or about what the dishwasher stands for.

Which means the useful practice is to defer during the bad state and then check, once recovered, whether there was a real subject underneath.

Frequently there was not. Occasionally there was, and it deserves a proper conversation rather than the one that happened at eleven at night.

The recovery afterwards

Short and worth doing.

An argument caused by exhaustion does not require a resolution, and attempting one generally manufactures a subject.

What it does require is a brief acknowledgement — that it was not really about the thing, that you were not at your best — which prevents the incident from being filed as evidence.

The pattern to watch

One caveat on the whole framing.

Where a household is consistently exhausted, consistently stressed and consistently short with each other, the tiredness is not an occasional explanation. It is the standing condition.

At that point the useful intervention is structural — the workload, the schedule, the support available — rather than another agreement to be more patient.