Check the diagram and you’ll notice that each of our eyes is cleverly
“wired” to send the left visual field to our right brain hemisphere; and
vice-versa, right-side information is channeled to the left hemisphere.
Even if we were to lose one eye, our brain would still make this distinction.
In the previous test you chose face A as happiest.
Over 70% of people taking this test choose face A. This suggests that you, like majority of the population use your right-hemisphere for judging facial expressions. Notice that you favoured the left-side smile of face A.
You are also probably right-handed. Right-handedness is normally associated with language abilities in the left hemisphere and facial evaluation in the right hemisphere.
Interestingly, some 60% of left-handers choose face B in this test, they are wired the other way round to you. Their facial evaluation resides in their left brain and speech in their right.
This is not just biologically interesting,
there are practical consequences.