An illicit theory of costly signaling

I’m sympathetic to the view that many human behaviors are for signaling. However so far it doesn’t seem like a very tight theory. We have a motley pile of actions labeled as ‘maybe signaling’, connected to a diverse range of characteristics one might want to signal. We have a story for why each would make sense, and also why lots of behaviors that don’t exist would make sense. However I don’t know why we would use the signals we do in particular, or why we would particularly signal the characteristics that we do. When I predict whether a middle class Tahitian man would want to appear to his work colleagues as if he was widely traveled, and whether he would do this by showing them photographs, my answers are entirely based on my intuitive picture of humans and holidays and so on; I don’t see how to derive them from my theory of signaling. Here are two more niggling puzzles:

Why would we use message-specific costly signals for some messages, when we use explicit language + social retribution for so many others?

Much of the time when you speak to others, your values diverge from theirs at least a little. Often they would forward their own interests best by deceiving you, ignoring social costs and conscience. But even in situations where risks from their dishonesty are large, your usual mode of communication is probably spoken or written language.

This is still a kind of costly signaling, as long as if the person faces the right threats of social retribution. Which they usually do I think. If a person says to you that they have a swimming pool, or that they write for the Economist, or that your boyfriend said you should give his car keys to them, you will usually trust them. You are usually safe trusting such claims, because if someone made them dishonestly they could expect to be found out with some probability, and punished. In cases where this isn’t so – for instance if it is a stranger trying to borrow your boyfriend’s car – you will be much less trusting accordingly.

This mode of costly signaling seems very flexible – spoken language can represent any message you might want to send, and the same machinery of social sanctions can be used to guard many messages at once. And we do use this for a lot of our communication. So why do we use different one-off codes for some small class of messages? What sets that class apart?

The main obvious limitation of language + social sanctions is that it requires a threat of social retribution large enough to discourage lying. This might be hard to arrange, if for instance there are very large gains from lying, if lies are hard to find, or if the person who might lie doesn’t rely on good relationships with the people who might be offended by the lies. So maybe we use non-costly signaling in those cases?

In many of those cases we do use a kind of costly signal, yet a different variant again to the kind hypothesized to covertly pervade human interactions. This type of signal is the explicit credential. When a taxi-driver-to-be takes a driving test or has a background check, then displays his qualifications, this is a signaling display. Acquiring these documents is much cheaper for a person who can drive and has a clean background, and you (or the taxi company) know this and treat him differently if he makes these signals. I say this seems different from the social signaling we usually think of because it is explicitly intended as a signal, and everyone readily accepts that that is the goal, and is fine with it. Which almost brings me to the next puzzle. In conclusion, it’s not clear whether the signaling that we usually think of as such mostly occurs in situations where language and social sanctions are hard to use, but it is at least not the only thing used in such cases.

Why is signaling seen as bad? Why don’t we know about our own signaling?

It is often taken as given that signaling is bad. If a person comes to believe that a behavior they once partook in is for signaling, it is not unusual for them to give it up on those grounds alone, without even noticing the step of inference required between ‘is for signaling’ and ‘is bad’. A signaling theory is apparently a cynical theory.

This seems odd, as badness is not implied at all by the theoretical costly signaling model. There, signaling can be bad or good socially, depending on the costs of carrying it out. There are gains from assorting people well – it is better if the good people do the important jobs for instance – but no guarantee that the costs of the fight won’t overwhelm the gains.

Another related oddity is that people are supposed to be mostly unaware that they are signaling. Nobody bats an eyelid when a person claims to realize that they were doing a thing for signaling in the past. Talk of signaling is full of ‘Maybe I’m just doing this for signaling, but …’. Yet in the naive model of human psychology, it is at least a bit odd to be unaware of your motives in taking an action until months later. It’s true that people quite often don’t appear to have a good grasp of their own drives, yet in signaling this seems to be the normal expectation. And again, the theoretical model of costly signaling says nothing of this. It’s not obvious why you should expect this at all, given that model.

Another reason this seems strange is that we do have a lot of other explicit forms of signaling that we are aware of and ok with, as mentioned above (qualifying tests, ID cards, licenses). It is not that we have a problem with spending effort on almost-zero-sum games, or paying costs to look good.

An explanation

I’d like to suggest an explanation: costly signaling (of the message-specific unconscious variety) is largely used to communicate illicit messages. For instance, many messages about one’s own wealth, accomplishments, status, or sexual situation, and other messages about social maneuvering and judgement, seem to be illicit. Such things are also common targets of signaling theories, though my reasons for suggesting this explanation are mostly theoretical.

Illicit messages can’t be honestly transmitted using language and social norms, for a few reasons. Illicit things often shouldn’t be said explicitly, for plausible deniability, to avoid common knowledge, etc. This means you generally can’t use language to communicate illicit things, because language is explicit. This is one reason language + social retribution doesn’t work well for illicit messages. But also if you successfully have plausible deniability or prevent the message spreading far, both of these make social retribution hard to arrange. So implicit messages are quite hard to make honest through language + social retribution. Or through explicit verification for that matter, which is similar. Yet if such messages are to be listened to at all, they need some other guarantee, which other kinds of non-explicit costly signaling can provide. So this would explain the first puzzle.

If we had a set of signals just for illicit messages, it would be very silly to claim that we were aware of sending such things, and perhaps upsetting to believe that we were and to lie about it. So for the usual reasons that people are thought to be unaware of their less desirable tendencies, it wouldn’t be surprising if people were unaware of the signals they were sending. And if such signals were largely used for illicit messages, it would be unsurprising if we universally thought of signaling as an illicit activity. So this would explain the second puzzle.

6 responses to “An illicit theory of costly signaling

  1. This is pretty much the homo hypocritus story about signaling. We try to covertly communicate to coordinate our evasions of over norms. So we can’t use language overtly for that. So we are forced to rely on other forms of communication. On standard norm is against bragging, and so we especially need covert ways to brag. Thus the costly signals that show our abilities are covert, and we are not consciously aware they serve these functions.

    • Thus the costly signals that show our abilities are covert, and we are not consciously aware they serve these functions.

      You’re implying (for example) that you aren’t consciously aware that a major mental drive fueling your intellectual endeavors is to signal intellectual aptitude? If it weren’t for your scientific insights re signaling, you would really believe it’s all simply in the interest of finding truth? (Or something like that.)

      I recall a survey of scientists from way back when; they freely admitted that their primary motive was fame. Humans ordinarily avoid reflecting much on their signaling; but they signal with conscious awareness (in cases other than adversarial social coordinations, particularly against authority).

      I think there’s an element of motivated obfuscation in the Hanson/Grace school of signaling theory. Downplaying the conscious character of signaling serves to increase the social tolerance of signaling, in homo hypocritical fashion. Also suspect is the avoidance of providing any example of subconscious signaling.

  2. The idea that unconscious signals serve illicit ends of coordinating to evade authority is developed at length in “Why We Lie: The Evolutionary Roots of Deception and the Unconscious Mind ( )

    He marries speculatively this theorizing with Robert Langs’s transactional reinterpretation of psychoanalysis. The messages he’s interested in are from one subconscious mind to another and usually require a symbolic reading.

    You might think of what I’ve described, if you accept it, as a third form of signaling. Where I have a very primitive disagreement with you regards your claim most of our signaling (of the second kind) is hidden even from ourselves. I wonder why you think that? Is it perhaps that, when your signaling is pointed out to you, it’s news?

    This seems like an important point, and disagreement on it seems odd to me. Perhaps an example can help. One common form of signaling in the form of bragging is name dropping: Like I dropped the Name “Robert Langs,” feeling confident that you wouldn’t know who he is. Not-so-subtle one-upsmanship, but surely a way people use signaling to brag. Would you really have assumed I didn’t consciously know what I was doing?

    I think the deep signaling that the subject of the book I mention and the type 2 signaling are covert for different reasons. Some transgressions we do hide even from ourselves. These involve coordinations to evade authority. But we don’t hide ordinary norm violative tendencies from ourselves. When we brag, we’re signaling but not to coordinate against others but rather to augment our own market value. It’s not hidden from ourselves, just from others. It’s hidden from others because if the signaling is transparent, its credence decreases. This can be easily explained: a signal is more costly if produced inadvertently. When you bring this kind of signaling to someone’s attention, it means they’ve been found out. They stop because the signal has been degraded.

  3. I say this seems different from the social signaling we usually think of because it is explicitly intended as a signal, and everyone readily accepts that that is the goal, and is fine with it.

    That you need to make this theoretically artificial distinction is a demerit. Many signals are only slightly less sanctioned socially than these “official” signals. For instance, to take just one arbitrarily, when sports fans wear their team’s “gear”; or (a little different and costlier), when they makes bets favoring their team to signal their favoritism.

    And the “official” signals are subject to the same principles as the informal signals. For example, If someone is overly ostentatious about the credentialing signals, this will degrade the signal. (The logic: anybody can find some impressive document to display.) The parvenu error.

    Signals often are not illicit. Signaling the team one is on (or what ideology one supports) usually is not illicit at all. So the fundamental reason we signal isn’t to break norms illicitly. (Only type 3 signaling, which you don’t discuss, is necessarily about that.) The basic reason humans use signaling rather than language is that talk is cheap, not that it’s unambiguous–which it really isn’t.

    We signal consciously, and we do it in near-mode. If we feel reproval at signaling accusations, its because of the content that’s signaled, not the fact that signaling is used. We’re quite comfortable with signaling in the many instances when it isn’t status self-aggrandizement that’s the objective.

    (I’ve applied my understanding of signaling theory at )

    To end on a positive note, I think it’s good that you’ve made explicit the signaling implications of Hanson’s homo hypocritus.

  4. I think it’s not about what you signal but how. Honest signals are socially acceptable, dishonest signals are not.

    Say, you think you are highly intelligent. You want to signal it, or in more normal terms, get some recognition as a genius. You would do something that is known with very high certainty to require very high intelligence (certainty is necessary because intelligence is rare), then you can list that on your website, in your CV, even be known for it. Contests, impressive accomplishments, and so on. That’s very socially acceptable – just look at chess championships.

    But you may fail at this type of signalling, because it is a honest signal, and a honest signal requires you to have the quality being signalled.

    The non socially acceptable ways to “signal intelligence” are those that concern itself with imitation of outward appearance of a genius, which do not in fact require genius intelligence – there is a plenty. Those are not socially acceptable because of the norms against deception, even though deception in question may not be exactly lying – with Dunning-Kruger effect, one may remain entirely unaware that they aren’t what they imitate. And those have a high cost – they only deceive a fraction of people, while most rely on the honest signal described above.

    • The biggest reason some signaling is socially unacceptable is that it fails. Failed signaling is perceived as deceit. Whether it really is deceitful is beside the point.

      Much signaling depends on apparent inadvertence. If you ask me some arbitrary intellectual question and I seem brilliant, offering the same information without your asking will be much less impressive. Anyone can find some topic he can go on about. You’ll view me as trying to impress you; unconsciously, you’ll see me as a liar because a failed signal is interpreted that way. It doesn’t demonstrate what it’s supposed to.

      If I enter a profession because I think it will prove my genius, this degrades the signal. Not completely but somewhat: It would be a better signal if I followed my interests rather than tried to prove my intelligence, again because of the element of apparent inadvertence, which means I’m sampling more broadly rather than cherry picking how I try to distinguish myself.

      Consider some high-IQ societies based on extraordinary test scores. They aren’t high status because the members are so obviously motivated to score high that the test doesn’t necessarily measure their intelligence, more their desire to choose something they can do very well on and their willingness to devote great effort to mastering a narrow skill. If someone who wins a chess championship admitted his motive was solely to prove to the world how smart he is, that would diminish the value of the signal. Similarly for academic pursuits.

      Where the deceit theory fails is that “honest” signaling is often, in fact, socially unacceptable. Take conspicuous consumption, a prototypical form of signaling. Displaying wealth in too obviously ostentatious fashion is unacceptable despite the fact that the signaler is really fabulously wealthy. The signal, because it is so contrived (not inadvertent) rings false, although it’s an accurate signal and everyone knows it.

      The importance of inadvertence drives theories like Robin espouses that claim that we resent status signaling because of evolved dispositions to reject and oppose those who try to elevate their status above their peers. There are grounds for this analysis in evolutionary psychology, but your examples of honest signaling (which are also examples of signals that appear honest) show that we don’t necessarily react against every person who signals merit. This tells against Robin’s (standard) view.

      Because effective signaling is inadvertent, dense signalers have incentives to claim that signaling is generally inadvertent (unconscious).

      With regard to signaling altruism, they’re particularly motivated to deny the fact that signaling is a conscious process. Someone who admits that he or she engages in altruism to enhance their own status invalidates their own signal at a fundamental level.


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