MAS 960  ·  Signals, Truth & Design Seminar  ·  Fall 2007

09.11 introduction to signaling

This week we will be looking in depth at the definition, structure and dynamics of signaling . We'll look at the different mechanisms that make signals reliable and at how the form and the meaning of signals are connected. This material is the conceptual basis for the rest of the course; it is these models that we will be applying to various daily phenomena.


Donath, Judith (forthcoming). Signals, cues, and meaning (Draft)
Maynard Smith and Harper. (2003) Animal Signals Chapter 1. (available outside room 392)
optional: Grafen, Alan. (1990). Biological signals as handicaps. Journal of Theoretical Biology 144 517-546 (available outside room 392)
optional: Dawkins, Marian Stamp and Guilford, Tom. (1991). The corruption of honest signaling. Animal Behaviour 991) 41 865-873. (available outside room 392)


  1. Read the papers. My chapter and the Animal Signals chapter will provide you with an introduction to signaling theory. The Grafen paper is important because it reframed Zahavi's concept of handicaps as game theory nd made it credible to a wide array of scientists. The Dawkins and Guilford paper introduces the notion of conventional signals and shows the importance of looking at signaling as a communication system rather than just focusing on the signal itself.

2. Answer the following questions:

  • Why are there deceptive signals? Why are they a problem - and to whom?
  • What is the difference between an unintentional cue and a signal? Why does it matter?
  • What characterises signaling among humans (as opposed to animal communication)?
  • What are signals of need? What is difficult about interpreting them?

3. Describe two examples of signals in human society - one that is an example of an assessment signal and one that is a conventional signal.

For the first (assessment):

  • how is the signal related to the quality?
  • Is the signal costly? If so, how?
  • Is it entirely reliable or are there deceptive forms of the signal?
  • Is there a "need" compenent here - i.e. do you see this signal as indicating need or seriousness about some other quality?

For the second (conventional):

  • how is the signal related to the quality?
  • Is this convention widespread or local to a small group?
  • Is the signal frequently made deceptively?
  • Is there a sanction against it?

For both:

  • what are the costs to the receiver in assessing the signal?
  • Is the signal ambiguous - is there likely to be a mismatch between the sender's intent and the receiver's impression - or is there general agreement abou the meaning of the signal?
  • What are the non-signaling costs and benefits of the signal? How do they affect its effectivenss?

Please link your essays by midday on Monday 9/17.