IDEAS home Printed from
MyIDEAS: Log in (now much improved!) to save this paper

The Death of Costly Signalling?

Listed author(s):
  • Michael Lachmann
  • Carl T. Bergstrom
  • Szabolcs Számadó

How do organisms communicate honestly despite conflicts of interest? Over the past quarter-century, the "costly signalling" hypothesis -- that signal honesty can be ensured by appropriate signal cost -- has emerged as the dominant explanation for this puzzle. First proposed by Zahavi [1, 2] and formalized by Grafen [3] and Godfray [4], this hypothesis has led to a proliferation of theoretical models [5, 6, 7, 8, 9, 10, 11, 12, 13, 14] and empirical tests (reviewed in [15, 16, 17, 18]). Unfortunately, these empirical studies suggest that honest signalling is not always accompanied by the predicted signal costs (reviewed in [12]), and some signalling systems (including human language) appear not to require signal cost at all. In response to these difficulties, researchers have attempted to identify special mechanisms by which signalling can be honest even with low or zero signal cost (also reviewed in [12]). Here, we show that no special mechanism is necessary. While the cost of out-of-equilibrium signals plays an important role in stabilizing honest signalling, the signals actually employed at equilibrium need not be costly. Therefore, even unrelated individuals with conflicting interests can communicate honestly using cost-free or very cheap signals; contrary to the "handicap principle," waste is not required to ensure honest signals. We illustrate this by constructing examples of cost-free signalling equilibria for the two paradigmatic signalling games of Grafen [3] and Godfray [4]. Our findings (1) significantly revise previous theoretical conclusions regarding the requirement for signal cost in honest signalling systems, (2) explain the discrepancy between empirical signalling studies and theoretical predictions, (3) suggest why some animal signals use cost to ensure honesty while others do not, and (4) provide ways in which signalling theory can be used to address the "problem of deception" in the evolution of human language.

To our knowledge, this item is not available for download. To find whether it is available, there are three options:
1. Check below under "Related research" whether another version of this item is available online.
2. Check on the provider's web page whether it is in fact available.
3. Perform a search for a similarly titled item that would be available.

Paper provided by Santa Fe Institute in its series Working Papers with number 00-12-074.

in new window

Date of creation: Dec 2000
Handle: RePEc:wop:safiwp:00-12-074
Contact details of provider: Postal:
1399 Hyde Park Road, Santa Fe, New Mexico 87501

Web page:

More information through EDIRC

References listed on IDEAS
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:

in new window

  1. Rubinstein,Ariel, 2000. "Economics and Language," Cambridge Books, Cambridge University Press, number 9780521789905, March.
Full references (including those not matched with items on IDEAS)

This item is not listed on Wikipedia, on a reading list or among the top items on IDEAS.

When requesting a correction, please mention this item's handle: RePEc:wop:safiwp:00-12-074. See general information about how to correct material in RePEc.

For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Thomas Krichel)

If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

If references are entirely missing, you can add them using this form.

If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.

If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.

Please note that corrections may take a couple of weeks to filter through the various RePEc services.

This information is provided to you by IDEAS at the Research Division of the Federal Reserve Bank of St. Louis using RePEc data.