Lines often determine the format of a photograph.
(See Seeing Lines 1)
The subject pulls us in a certain orientation.
Do our cameras pull as well?

Cameras have their own dominant line too:
They are usually wider than they are tall.

Does that encourage us to shoot in landscape?
For portrait, you have to twist your hands.
It's less comfortable — do we do it less often then?

Which of these cameras would make you more likely to shoot vertically?

Does camera design favor the landscape format?

(And... if we think about smartphones for a moment:
How often do we hold them horizontally when taking pictures?)

My solution:
A battery grip.
I find the name misleading.
Yes, it also holds batteries.
But for me, the real advantage has always been:
How easy it makes shooting vertically.

Now my tool no longer subtly influences my behavior.
Now I have freedom and choice again.
Since then, I have been photographing more freely.