DEEP DIVE

We spend most of our lives indoors, and we mostly accept the rooms we are given. But a study of Chinese university entrance exams, using seats that were assigned at random, found that one detail of the room made a measurable difference to how well people thought.

The problem with studying whether your environment affects your brain is that people choose their environments. The person with the corner office and the view is usually the person who was already doing well. Any difference you measure could be the office, or could be everything that got them the office.

The Chinese national college entrance exam solved this by accident. It is a single test that decides university admission, and it matters enormously. To prevent cheating, county authorities assign students to rooms and seats at random, scattering classmates who know each other. Every room holds thirty students in the same grid, five columns by six rows. Two of those columns sit against windows.

Here is the detail that makes the study work. Those two window columns are not the same. Column 5 looks out at the outside world. Column 1 also sits by a window, but that window faces an open corridor, so the view is blocked. Two seats with the same light, the same draught, the same distance from the front, and only one of them with something to look at.

The researchers took records for more than 3,700 students who sat the exam in one county in 2019 and checked the randomisation held. Seating showed no relationship with gender, ethnicity, age, or whether a student came from a town or the countryside.

Students in Column 5, the seats with a real view, scored 9.1 percent of a standard deviation higher than students in the middle of the room. Students in Column 1, next to a window with a blocked view, showed no benefit at all. Their scores were indistinguishable from everyone else's.

That figure works out to roughly nine points on the exam. In a province with 210,000 science-track candidates, nine points can move a student up around 8,100 places in the ranking. And it showed up where it counts: students seated by a window with a view were 2.8 percentage points more likely to win a place at a first-tier university.

To check the result was not driven by a few lucky students, the researchers broke it down seat by seat. Every single seat in the window column outperformed the baseline. The weakest of them still beat 23 of the 24 seats elsewhere in the room.

So why would a view help? The researchers point to attention restoration theory, the idea that looking at a natural scene gives the mind a brief rest and lets concentration recover. Two further findings support it. The benefit was strongest among male students, who tend to struggle more with sustained attention during long exams. And using teachers' written assessments of each student's classroom behaviour, the researchers identified those who find it hardest to concentrate. Those students gained the most from the window.

The comparison with other environmental research is striking. In the same exam system, a one-standard-deviation rise in temperature has been found to cost students 5.8 percent of a standard deviation, and a similar rise in agricultural smoke costs 1.4 percent. A view out of a window was worth more than either.

Two honest caveats. This is a preprint, so it has not yet been through peer review. And it covers a single county in a single year, in a setting where sustained concentration is everything. The authors note that when a task does not demand continuous focus, a window might just as easily distract you.

MYTH BUSTER

Verdict: false, and one man proved it the hard way.

Dr Donald Unger spent fifty years cracking the knuckles of his left hand every day and leaving his right hand alone. After half a century, neither hand had arthritis. It earned him an Ig Nobel prize in 2009, and while a study of one man proves little, the larger work agrees with him. A 2011 study of 215 people aged fifty to eighty-nine, comparing those with confirmed hand osteoarthritis against those without, found no link regardless of how often or how long they had cracked.

There is a catch worth knowing. Habitual crackers in a 1990 study showed measurably weaker grip strength and more hand swelling. Neither is arthritis, but neither is nothing.

PILLAR SPOTLIGHT · NUTRITION & CELLULAR HEALTH

Vitamin B12 builds your red blood cells and keeps your nerves working. Run low for long enough and it can cause anaemia, nerve damage, and problems with memory and reasoning.

The catch is that doctors do not test for it routinely, and the early symptoms are easy to dismiss. Fatigue, weakness, constipation, poor appetite. They look like a hundred ordinary things.

Most people get the 2.4 micrograms a day they need from meat, fish, eggs and dairy. However, from about fifty, your stomach makes less of the acid needed to release B12 from food, so you take in less of what you eat.

The fix is simple. Fortified cereals and yeast products, or a supplement, will usually cover it. If you have the symptoms, ask your doctor for a blood test. It is cheap, and catching this early is a great deal easier than repairing the damage later.

A seat with something to look at, a habit you can stop worrying about, a blood test worth asking for. Small things, easily overlooked, which is usually where the useful ones hide. Thanks for spending part of your week with us.

Take care of yourself,
The Vitality Club