The stairwell decides first

A family that has just viewed two apartments in Ain Shams will tell you they chose on rent, size and the distance to school. Those are the reasons they give, and they believe them.

Watch the visit itself, though. The first building has a dark stairwell that smells of someone else's lunch, and the porter is asleep in his chair. The second has a swept entrance, a window on every landing, and a neighbour who holds the lift for them. By the time they reach the second front door, the decision is mostly made.

Within the hour the feeling has turned into a story. The first place was badly run, probably damp, not right for the children. The second was a good building. The rooms and the rent arrive last, and they are read kindly in one case and harshly in the other, to support a verdict that was already in.

We like to believe we weigh things up and then feel good about the result. Mostly it runs the other way round. We feel, we explain the feeling to ourselves, and then we collect whichever facts agree.

This matters to anyone hoping to help people choose well. Better information helps less than it should, because it gets read through a mood that has already set. The useful work is usually earlier and smaller than we think: the light on the landing, the person at the door, how the first two minutes go.

If you want someone to make a good decision, look after how the moment of deciding feels.