Common hair pulling expressions and sayings

Though hair pulling as a self-directed behavior is little known among the general population, references to hair pulling are in fact an everyday part of English colloquial expression.  The phrase, “to tear one’s hair out’ is one commonly used by English speakers and its meaning generally assumed to imply the frustration of an impulse, even by people who may have never pulled hair nor heard of trichotillomania. Indeed, colloquial references to hair are plentiful and the following is very much a truncated list:

To keep one's hair on (to stay calm)
To let one’s hair down (relax)
To make one’s hair stand on end (terrify)
To get in someone’s hair (to annoy)
To split hairs (to argue pettily)
To have a bad hair day (to feel unattractive because one's hair is restive)
To not have a hair out of place (to be tidy)

and, of course, the above mentioned,
To tear one's hair out! (to be at one's wits end)

      It is fascinating that hair references should abound, particularly the way that hair and mental states are so entwined in folk consciousness.  And yet, the idea that hair may play a role in homeostatic regulation and that hair pulling is such a little known disorder is in this context quite surprising.  Hair and hair related actions or grooming behaviours are so much part of what makes us human it is that it is perhaps more difficult to get clear perspective on the function it serves for us - why we do it and the benefits that accompany these actions.