A study conducted at the University of Iowa has challenged a century-vintage cornerstone of behavioral science, suggesting that living creatures do not function as predictable machines. The research, led by Ed Wasserman, demonstrates that even when consistent rewards are provided, behavior can remain unstable and unpredictable.
The experiment involved six pigeons over an eight-month period. The birds were presented with a choice game featuring five buttons of varying colors and shapes on a screen. To receive food, the pigeons had to touch all the buttons in any random order. notably, they were rewarded regardless of the sequence they chose. This process generated approximately 30,000 individual choices.
Under the “law of effect”—a behavioral theory more than 100 years old—repeated rewards are expected to lead to a single, efficient, and fixed sequence of actions. Although, the University of Iowa findings contradicted this established law. While the pigeons developed preferences for certain sequences, they never adopted a single, stable strategy.
According to the researchers, favorite combinations appeared and disappeared without any clear cause. While the behavior became less random over time, it remained fundamentally unstable. “They continue to show variation, even when that is strictly not necessary,” Wasserman stated.
The research team describes this phenomenon as “living on the edge of chaos,” characterized by a state that is neither pure chance nor a rigid routine. This persistent variation may be an adaptive trait, as avoiding fixed habits prevents an animal from becoming vulnerable in changing environments.
The implications of the study may extend beyond avian behavior. Co-researcher Odysseus Orr suggests that this same inclination toward variation could play a significant role in human creativity and improvisation. The findings underscore that while rewards influence decision-making, they do not dictate it entirely; even after thousands of reinforcements, room for experimentation and chance remains.
