If you are worried, anxious, angry, you knit the brows into a “frown,”
and the same is true if you are trying to recall some lost thought. Why
should the same outward expression be the symbol of so many differing
emotions? There being so many varying emotions, it seems strange, at
first sight, that the frown should represent them all! Why is this? Why
do we frown, on these various occasions?
A frown is due, physiologically, to the bringing together and lowering
of the eye-brows and the muscles just above them. This is accomplished
by the “corrugator” muscles, whose duty it is to contract the brows.
Now, a man may be working along for several hours, on an abstruse
problem, and never contract his brows; suddenly he does so! He has
struck something in his line of thought which is particularly difficult
or displeasing to him. It is the occurrence of this emotion which has
induced the frown.
Anything which induces an unpleasant emotion, therefore, may induce a
frown. If the food is not good, a man may frown at his wife; if the
milk is too cold, a baby will frown before crying. During intense
thought, the brows are only contracted when an idea, or a word, or
mode of expression is lacking. This sub-conscious irritation is then
expressed in a frown.
Another cause had probably strengthened the habit of frowning. That is
the endeavor to see more clearly at a distance. Short sighted people
often contract the eyes and the forehead in an effort to see with
greater distinctness. (This action has, in fact, given rise to the term
“Myopia,” from the Greek.)
Contraction of the brows also tends to shut out an excess of light,
which would also be an impediment to clear seeing. Frowning, therefore,
serves several good purposes, and may be brought about by several
distinct causes.