The Price of Tears
Why do we cry?
The common behavior of mankind is the system of reference by means of which we interpret an unknown language.
If a lion could speak, we could not understand him.
—L. Wittgenstein
The best refutation of cultural relativity is the activity of anthropologists themselves, who could not understand or live within other human groups unless the inhabitants of those groups shared assumptions that were, in fact, very similar to those of the ethnographer. Like fish unaware of the existence of water, interpretativists swim from culture to culture interpreting through universal human metaculture. Metaculture informs their every thought, but they have not yet noticed its existence.
—D. Sperber
Semiotics made a big deal out of the concept of the arbitrariness of signs. Sure, there is often "no necessary connection" between a sign and what it signifies; say "dog" and a dog. But for many in the humanities and social sciences this notion that the relationship between a sign (signifier) and its meaning (signified) is arbitrary, or purely conventional, became a more general philosophy of social constructivism and a battle cry that carried a certain "emancipatory potential". After all, if "there is nothing outside the text" (Derrida), if language constructs our reality, and if the relation between different social phenomena is arbitrary and by convention just as it is between the signifier and the signified, then perhaps other conventions and ways of being are possible? The implicit promise of a possible change had a certain allure that motivated adoption of "semiotics" in literary theory, psychoanalysis, cultural and gender studies, film and media studies and so on.
On the other hand, there is an important difference between semiotics and signaling theory (as it appears in evolutionary biology and game theory) in terms of how they view communication. In signaling theory, for a signal to be credible or honest, it has to be costly and thus hard to fake. This fact by itself already undermines the extreme thesis of arbitrariness.
Take crying as an example. As Daniel Sznycer and colleagues argue in a forthcoming paper, tears may function as "plea for receivers to minimize the costs imposed on the tearer… common when the tearer has lower formidability or wherewithal than receivers do".
The question is: how could shedding tears get off the ground as a signal? It's not by mere convention since that would require the actors to agree on the code before communication begins. And even if they somehow agree, how can this signal retain its credibility through time?
It's not only that conventionality and arbitrariness of the signal couldn't get the signal off the ground; a signal cannot obtain or maintain credibility by being "arbitrary": it has to carry a cost (especially, if there is a risk of deception).
So why would crying be a good way of communicating to others to minimize the costs that the tearer endures?
First, why eyes?
people already infer information from the the eyes of other people (e.g. by following a person’s gaze one can infer what is the object of that person’s attention and interest)
Second, why tears?
tears originally evolved to "lubricate and nourish the cornea and to keep it free of dust and bacterial infection, to protect the eye against physical and chemical damage". So the emotional system can co-opt an already existing physiological system. It's cheaper that way.1
shedding tears is not easy to consciously control which makes it a somewhat hard-to-fake signal.
tears blur the vision of the tearer thus presenting him with a handicap which can function as a honest signal of submission (e.g. in a fight) or a plea for help (crying advertises inability to see which advertises incompetence/vulnerability).
compare cutting your own hand as a signal that you no longer present a threat to someone in hand-to-hand combat2 and handicapping yourself by producing a visual impediment—it is clear that the latter is superior because it makes a better trade-off between the handicap and the duration of the handicap, tears leaving no permanent damage that is. Likewise, compare smiling with tearing as a way of signaling you no longer present a threat—it is also clear that the latter is more “honest” since it really does create a handicap unlike a smile.
Hence, tears in eyes can mean "I'm not a threat to you" or "I cannot see, therefore I need help". The communication is not achieved by the sender and receiver sharing the same communication code, i.e. a set of rules that pairs signs and their meaning—it is achieved by one side providing evidence of the meaning being conveyed. But for something to be a piece of evidence, it cannot be purely arbitrary or conventional. And it cannot be cheap. It can't get off the ground that way! The evidence has to be in inferential relation, whether deductive (logical) or inductive (probabilistic), with the thing it is an evidence of.
Onomatopoeic words and bouba/kiki effects are another example where the relation between words and their meaning is not completely arbitrary. Both violate arbitrariness via imitation, phonetically or by mouth movement (although see here for an alternative account of the bouba/kiki effect). With tears as signals, however, arbitrariness is violated not via imitation of some sort but rather because the signal (tears) is causally related to the meaning. In that way, the signal functions as evidence that could be used by observers to infer what it “signifies”; from “visual impediment” an observer can infer “incompetence”, “vulnerability” or “not a threat”.
And so emotional tears can evolve in the following manner:
at first they only protect the eye
but then observers can take tears in one’s eyes as a cue that one is experiencing a visual handicap (e.g. something got into his eye)
when tears have become a cue for one’s visual impairment, the signal can build on top of that cue and become a communicative device by actually producing a visual handicap
My readers may notice that the logic of the above explanation for the evolution of emotional tears is similar to the logic of my explanation for the evolution of overcofindence:
at first self-confidence reflects person's evaluation of his own competence in a given domain
which leads people to attend to person's self-confidence as a cue, or a quick-and-dirty heuristic, for inferring person's competence in a given domain
but once this logic is established, pressure arises to develop overconfidence as a tool for persuading others of person’s own competence
The difference is that in the case of overconfidence, we cannot talk of an “honest” signal since overconfidence implies an inaccurate representation of reality. Overconfidence is subjected to Goodhart's law: when a measure (indicator or a cue) becomes a target of optimization, it ceases to be an equally good measure (indicator or a cue).
I should add that the authors of the paper do not consider the handicap hypothesis (they do only in relation to tears’ metabolic production cost, not in relation to visual perception) although it does seem to me that this is the most plausible explanation for how could tears as a signal get off the ground. Handicap “scaffolds” the relation between the signal and its meaning thus affording us with the non-arbitrary relation between the two—the signal is the evidence of a handicap.
An interesting question that may arise is whether tearing is subject to Goodhart’s law. One thing to note here is that even if tears become “hacked”, they still present the tearer with a visual handicap although it is unclear what is the relevance of this fact outside the context of hand-to-hand combat.
The authors of the above paper do address this issue:
Here is my short exchange with one of the authors of the paper on Twitter. As I point out there, tear-receiver's negative revaluation of the tear-sender assumes that the relation between the signal and its meaning is already established. But the important question is how is it established in the first place? It seems to me that revaluation can be part of explanation for the maintenance of the signal over evolutionary time but not how tears get off the ground as a signal.
We would have to know more about the natural history of combats to assess to what extend tearing affords the sender with a handicap in a hand-to-hand combat. I assume that hand-to-hand fighting is relevant here since fighting with weapons can take place at a distance that would nullify the visibility of tears.
I should note that physiological system being co-opted for emotional tears is not completely identical to the one used for lubrication and eye-protection since there is a chemical difference between emotional tears, basal tears and reflex tears.
If that sounds too extreme, consider the Japanese ritual Yubitsume in which a person cuts portions of his little finger in order to atone for offenses done to another person. The act gains credibility as a signal of remorse precisely by the offender imposing a cost to himself, i.e. through a self-handicap. Wikipedia’s article mentions that “in Japanese swordsmanship…, the little finger's grip is the tightest on the hilt. A little finger-amputee was therefore unable to grip his sword properly, weakening him in battle and making him more dependent on the protection of his boss.”