A proper scientific philosophy of behavior may allow one to tackle traditionally inexplicable and impenetrable questions. One example thereof is nest building in animals – chiefly but non-exclusively in birds. How does such a seemingly complex set of behaviors arise in every generation despite no explicit learning? Radical behaviorist theory will lead the explanatory way.
Traditional notions
Judging by the first paragraph, one might get an impression that there is a dearth of explanations for nest building. Of course, that is not the case as many variations may be found. Nevertheless, after getting acquainted with widely espoused arguments, one will be left wanting for more.
Most reasoning in the current topic is fallacious and marred by teleological overtones. It might be said that birds build nests “to lay eggs and keep them safe, to protect against predators, to raise chicks, to improve survival chances”. The words “to” or “in order to” should raise alarm bells for any scientifically minded person as these are references to the future result and thus cannot possibly be an explanation for current behavior.
Another explanation is to refer to the “nest building instinct” or “nesting instinct” that the animal supposedly possesses. We will see shortly why this reasoning is circular and fictitious. A more sophisticated sounding variation here is to speak of genetic memory. Complicated as it may sound, it does only restate the initial problem in other words without invoking any explanations for the behavior. Let’s see what behaviorist theory has to offer.
Science of behavior to the fray
Let’s enjoy B.F. Skinner’s thoughts on the subject from the 1974 book About Behaviorism, in Chapter 3 Innate Behavior, section Intermingling of Contingencies of Survival and Reinforcement:
Imprinting. Operant conditioning and natural selection are combined in the so-called imprinting of a newly hatched duckling. In its natural environment, the young duckling moves toward its mother and follows her as she moves about. The behavior has obvious survival value. When no duck is present, the duckling behaves in much the same way with respect to other objects. (In Utopia, Thomas More reported, the chicks hatched in an incubator followed those who fed and cared for them.) Recently it has been shown that a young duckling will come to approach and follow any moving object, particularly if it is about the same size as a duck – for example, a shoe box. Evidently survival is sufficiently well served even if the behavior is not under the control of the specific visual features of a duck. Merely approaching and following is enough.
B.F. Skinner (1974, p. 40) – About Behaviorism
Even so, that is not a correct statement of what happens. What the duckling inherits is the capacity to be reinforced by maintaining or reducing the distance between itself and a moving object. In the natural environment, and in the laboratory in which imprinting is studied, approaching and following have these consequences, but the contingencies can be changed. A mechanical system can be constructed in which movement toward an object causes the object to move rapidly away, while movement away from the object causes it to come closer. Under these conditions, the duckling will move away from the object rather than approach or follow it. A duckling will learn to peck a spot on the wall if pecking brings the object closer. Only by knowing what and how the duckling learns during its lifetime can we be sure of what it is equipped to do at birth.
So we have to grapple with the fact that there are numerous instances of environment change that may reinforce behavior – what type of changes do so depend on the contingencies of survival of the species (or genetic history). Now, we can focus more specifically on instincts and nests. Here thoughts by Stephen Ledoux will enlighten us (published in 2013 in the Journal of Behaviorology, originally expressed in 1988):
Let me give an example. People often think of birds, and I pick another species, because it’s important to realize that we are not studying only human behavior, although that is our main concern at this point. But, for instance, people often look at birds and say gee birds have a nest–building instinct. Why do they build nests? Because they have a nest building instinct. How do you know they have a nest building instinct? Because they build nests. There is a certain circularity there, which is a problem. What we would prefer to say is that birds are pre–wired, in other words, their genetic structure is such that they are susceptible to having their actions of nest building reinforced by stimulus complexes such as those tightly intertwined twigs and weeds, which would not affect us at all. We could care less whether the weeds were intertwined. Doing the actions of building that nest is reinforced by that complex, and what that means is, the bird makes those actions more, and ends up building a nest. In a sense we would also look at the evolutionary history. Birds that didn’t build, or (no). Birds that were not adequately reinforced by the tightness of the sticks and weeds in their nests, built sloppy nests, and their eggs fell out, and that genetic pre–disposition did not get passed on. Those birds died out.
Stephen Ledoux – August 1988 Public Radio Interview of the Organizers of the First Behaviorology Convention (including Lawrence Fraley, Pat McKeown, Ernest Vargas and Julie Vargas) in Journal of Behaviorology (2013) 16(1) p. 17
At this point we know that if an organism displays any behavior, both contingencies of survival and contingencies of reinforcement affected the organism in particular ways for it to happen. As Skinner and Ledoux explained, almost any behavior might be reinforced with particular environmental changes where the organism is susceptible to reinforcement. The environmental changes might be increasing glucose levels in the bloodstream (eating), an approaching object (imprinting), building materials or intertwining twigs (nest building).
To put this point to rest, let’s visit thoughts from a couple of papers:
Paper strips served as an adequate reinforcement for the acquisition and maintenance of fixed-ratio barpressing in two pregnant rats. Prior to parturition, only a small daily nest was built and barpressing ocurred only in the dark part of the lighting cycle. Following parturition, barpressing for nesting material greatly increased, and sustained periods of responding alternated with nest-building and pup-care activities.
Oley & Slotnick (1970, p. 41) – Nesting material as a reinforcement for operant behavior in the rat
Nest building in mice has been shown to support key pressing (Roper, 1973b, 1975), but only under conditions in which the animal was able to perform the whole nest building sequence. (p. 42)
The most likely explanation of the decline in carrying is that it is inhibited by feedback from the nest or from nest building activities. It was not caused by the physical impossibility of getting more paper into the nest box, since the latter was rarely more than half filled, and I have observed the accumulation of much larger nests in pregnant animals. Since mice which have just completed a nest can be induced to recommence building immediately by removal of the nest (Roper, unpublished), it seems likely that the nest itself is a source of inhibitory feedback. (p. 53)
Roper (1976) – Self-Sustaining Activities and Reinforcement in the Nest Building Behaviour of Mice
Speaking more generally, we may acquaint ourselves with the classic 1950 paper by Paul Meehl where he provides analysis regarding the Law of Effect, which Skinner eventually named selection by consequences. Meehl argues that the idea of The Law of Effect includes no circularity and proposes both The Weak Law of Effect and The Strong Law of Effect:
e. Experimental Propositions: Sunflower seeds may be used to strengthen lever pressing, chain pulling, etc. In general, sunflower seeds may be used to strengthen all learnable responses in the rat. (This asserts the generality of the reinforcing effect of sunflower seeds and is what I am calling a trans-situational reinforcer law.)
f. Definition: A trans-situational reinforcer is a stimulus which will strengthen all learnable responses. <..> This definition with the immediately preceding experimental propositions enables us to say, “Sunflower seeds are a trans-situational reinforcer.”g. Experimental Proposition; All reinforcers are trans-situational. (The Weak Law of Effect.)
Meehl (1950, p. 73) – On the Circularity of the Law of Effect
h. Experimental Proposition: Every increment in strength involves a trans-situational reinforcer. (The Strong Law of Effect.)
In other words:
- The Weak Law of Effect – All reinforcers can strengthen a variety of behavior.
- The Strong Law of Effect – All “learned” changes in behavior involve reinforcers (learned meaning behavioral change not due to trauma for example).
Conclusion
Once again, we see the value of radical behaviorist analysis. Even if we don’t know the reasons for a specific instance of behavior, we are now equipped to look at the right place – contingencies of survival and contingencies of reinforcement (or the history of the species and the individual).
Radical behaviorist leftist 