This theory comes from evolutionary biology and explains how living beings communicate.
In this article we will learn what this theory consists of, what signals are, what types of signals exist, what types of communication can occur and how we can apply this theory to the study of human behavior.
Signal theory: what does it consist of?
Signal theory, also called signaling theory or in English signaling theory , is a theory that falls within biology (specifically, evolutionary biology). Try to explain how individuals or living beings communicate with each other through the emission of signals.
In addition, this theory has mathematical and physical bases in relation to communication systems. That is, it can measure the observed phenomena.
Thus, signal theory encompasses a body of knowledge related to evolutionary biology. It aims to explain and describe how animals trick each other through signals, and how this becomes an evolutionary pattern, important for the evolution of species.
As we will now see, the signals are issued to obtain a benefit, to manipulate or to protect against another deception. These can be of different types (sincere or not), as we will also see below.
The signals: what are they?
The fundamental concept of this theory is signals. But what do these consist of? They can be behaviors, traits, actions, sounds, structures… specific to each species; In addition, they have the function of benefiting the individual or animal that emits them (as well as their receptors, depending on the type of signal and the context).
The signals have a certain intensity, a certain cost and a certain purpose. Sometimes the signals are intrinsically associated with a risk for the issuer.
Signal theory states that signals are used to communicate; for example, through the signals that females emit to select their mates. The signals have the function of benefiting their sender, through the receiver modifying their behavior. That is, they are signals that are emitted to achieve something.
Signal theory holds that signals evolve, just like species. Thus, with evolution, the signals are better emitted and received. Through the study of these communication patterns, signal theory attempts to study the evolutionary patterns of species .
signal types
Broadly speaking, signals can be of two types: honest or dishonest . The former improve the receiver’s aptitude, and the latter harm it. Honest signals are usually sincere, while dishonest ones consist of deception.
One characteristic that all signals share is that they are intentional, deliberately produced; On the other hand, when they occur “by mistake”, unintentionally (for example, an animal that crunches leaves in its path and alerts predators), they are considered clues.
1. Honest signals
Honest signals are characterized in that the behavior or action emitted (signal) corresponds to the intention of the sender ; that is to say, the animal “does not hide anything”, it does not lie, it is a sincere signal.
These signals, like the dishonest ones, are issued to obtain some personal (or shared) benefit.
2. Dishonest signals
The dishonest signals proposed by the signal theory, on the other hand, are actually tricks that the animal emits ; that is, they appear to have an intention that is not real. In addition, this intention is negative for the receiver, and can harm him; for the issuer, on the other hand, it is beneficial. These signals are especially emitted by species that have some kind of evolutionary advantage.
Rogue signals can produce two types of consequences for species dynamics: extinction and fixation. Let’s see what each of them consists of:
2.1. extinction
According to signal theory, one consequence of rogue signals is their extinction. This occurs because the species are progressively able to detect when the signal is honest or dishonest, through repeated exposure to them.
In turn, this causes the benefits that the issuer initially obtained through its signal to be extinguished. It is an evolutionary process and in a certain way adaptive.
It can also happen, however, that over time dishonest signals are replaced by honest signals; this happens temporarily, and it happens so that they can be reapplied dishonestly (it is a kind of “deception” of the animal).
2.2. Fixation
However, another consequence can also occur with rogue signals, according to signal theory. Thus, the dishonest signals can end up being fixed in the population (when their presence increases). This causes the honest signals to be extinguished, because the dishonest ones prevail and dominate the environment.
Let’s take an example to understand it better. Imagine some birds that emit honest warning signals when a possible predator appears, in order to warn the other birds, to “protect” them. However, another group of birds ends up emitting the same alarm signals when they are competing for food with members of their own species, in order to “deceive” them into believing that a predator is really coming.
That is to say, in this case the birds use the signals as a way to keep the food, scaring away the other birds; It is a dishonest signal, because it is a deception, which ends up transforming from its initial form, maintaining itself and becoming fixed.
Handicap Principle
An interesting concept in signal theory is the concept of the “handicap” (or handicap principle).
Amotz Zahavi , an Israeli biologist, spoke of this principle in 1975. He argued that sometimes the emission of signals (both honest and dishonest) could suppose a very high cost for the species, which meant that only beings biologically more dominant could emit any type of signals.
This implies that beings with a clear biological handicap (less dominant) would have a handicap in emitting both honest and dishonest signals. Thus, only biologically dominant beings could emit signals, especially dishonest ones (deceit). This phenomenon is called the “principle of the handicap” .
Types of communication
As we have seen, signals are used to communicate (also to warn, to transmit…). But what is communicated? What types of communication exist?
The communication proposed by the signal theory can be of different types , and have different purposes; Thus, it can be a communication to cooperate (in order to obtain food, to mate sexually…), a communication to compete (relationships between prey and predators), a communication to obtain help (for example young that demand food), etc.
On the other hand, communication between animals can occur between enemies, or between “partners” or collaborators, as well as between members of the same species and between members of different species.
- Recommended article: “The 32 types of communication that exist (and their characteristics)”
The signal theory of human behavior
What is the use of signal theory if we think about human behavior? Do you have apps? The answer is yes; This theory has been used especially to explain patterns of interaction between people, as well as attitudes manifested in coexistence relationships.
One of its applications in social interactions is the study of the authenticity of different communicative patterns (intentions, goals, gestures…). This allows us to answer questions such as: When do we know that someone is lying? When is a signal honest? When does someone really have an interest in what we are communicating?, etc.
Bibliographic references
- Barrett L, Dunbar R, Lycett J (2002) Human evolutionary psychology. Princeton, NJ: Princeton University Press.
- Bradbury, JW; Vehrenkamp, SL (1998). Principles of animal communication. Sunderland, MA: Sinauer.
- Grafen, A (1990). «Biological signals as handicaps». Journal of Theoretical Biology 144 (4): 517-546.
- Guzman, G. (2018). The signal theory: is deception useful?. Psychology and mind.
To the classic question “what do you do?” I always answer “basically I am a psychologist”. In fact, my academic training has revolved around the psychology of development, education and community, a field of study influenced my volunteer activities, as well as my first work experiences in personal services.