Every planning meeting
somebody says it.
We cannot add that report.
The database will not take it.
Nobody argues.
You have said it yourself,
to a new starter,
with complete confidence.
Then one quiet week
somebody ran the test.
Ten times the reporting load,
on a copy of production.
The database
barely noticed.
The slow part
was one query
nobody had looked at,
and a connection pool
set to five.
Where did the belief come from?
Nobody could say.
Someone remembered an outage,
three years and two servers ago.
Everyone else
had simply heard it,
many times.
That turns out
to be enough.
In 1977
Lynn Hasher and her colleagues
gave people a list
of plausible statements,
some true and some false,
and asked how true each one seemed.
They came back
two weeks later,
and again after that.
Some statements
appeared every time.
Those were rated
more and more true,
whether they were true or not.
It is called
the illusory truth effect.
The best explanation
is fluency.
A sentence you have met before
is easier to process.
And easy
feels like right.
You do not remember
the source.
You remember
that it went down smoothly.
In 2015
Lisa Fazio and her colleagues
showed it working
even against what people knew.
Repeat a false line
about something they could answer,
like the name of the skirt Scots wear,
and belief in the false version
still went up.
Knowing better
did not fully protect them.
A team
is a machine for repeating things.
Standups,
retros,
the onboarding talk,
the old wiki page.
Every repetition
makes a claim smoother,
and not one of them
makes it more tested.
So when a sentence
feels too obvious to check,
ask where it came from.
Not whether it is true.
Where you first heard it,
and what that person had measured.
If nobody knows,
it is a rumour
with good attendance.
Write the team's load bearing beliefs down,
each with its evidence
and the date it was checked.
The database cannot take more load.
Measured when,
on which hardware,
by whom?
When one stops being true,
cross it out
where everyone can see.
And notice the moment
you say it yourself
to someone new.
That is how it spreads.
Familiar
is not the same as checked.
It only feels that way
from the inside.
– Serguey Asael Shinder
Top comments (0)