Reflexivity

• When I tap my brakes (to communicate rather than to brake), I'm trying to get another driver to brake.
• When I blink my high beams, I'm trying to get another driver to turn off vis high beams.
• When, on a highway, I switch on my turn signal momentarily but don't change lanes, I'm trying to point out to another driver that ve's left vis turn signal on.

What's more, I was reminded of the following thought from Analogies and Roles in Human and Machine Thinking.

If I touch my nose and say to you, “Do this!”, what will you do? Most people will touch their own nose. But why not touch mine? If I touch your nose, what will you do?

In other words, we can think about me touching my nose in two different ways. We can use a transitive verb, one taking a direct object—“I touch-nose me”—or a reflexive verb, one with the direct object built in—“I touch-nose-self”. However, as indicated above, the second way of thinking seems far more natural.

(Technically, I'm misusing the word “reflexive”. If you go by the dictionary definition,

Designating a verb having an identical subject and direct object, as dressed in the sentence She dressed herself.

the verb isn't reflexive, it's intransitive with an implied reflexive direct object, or something like that.)

Why does the second way of thinking seem more natural? I won't claim to have a definitive answer, but I will point out that there are a lot of similar verbs for which the transitive form just doesn't make any sense … “I wrinkle my nose”, for example, or even “I tap my brakes”.

So, what's the point? The point is that there's a general principle of communication at work here, a principle that allows me to refer to someone else's brakes by tapping my own. For lack of a better name, I'll call it the principle of reflexivity.