Stay Updated with the Popular Daily Science Newsletter 💡

Receive daily updates on groundbreaking discoveries, innovative research, and do-it-yourself science tips every weekday.

Robotic Innovation Sheds Light on Animal Social Behaviors

Researchers at St. George’s, University of London, have engineered a highly realistic android head to investigate whether chimpanzees can “pick up” yawns from robots. Surprisingly, findings indicate that they do, although the underlying reasons remain uncertain. This pioneering study, published recently in Scientific Reports, reveals that over half of the adult chimpanzees observed (57.1%) responded to the robotic yawn by mimicking the behavior. Additionally, many of these primates exhibited behaviors associated with preparing for sleep, such as lying down or gathering bedding materials, suggesting that the robotic yawn may serve as a social cue for rest. The precise neural or psychological mechanisms behind this response are still a mystery, but the research marks a significant step in understanding how contagious yawning extends beyond humans and other animals to include interactions with non-living entities like robots.

Lead researcher Ramiro Joly-Mascheroni explained, “Our results demonstrate that chimpanzees can exhibit contagious yawning triggered by a non-biological, inanimate agent-a humanoid android that appears to yawn. This suggests that the social and biological underpinnings of yawning may be more complex and widespread than previously thought.”

Deciphering the Enigma of Contagious Yawning

Yawning is a universal yet enigmatic behavior. While everyone yawns, scientists continue to debate its evolutionary purpose. One prevailing theory posits that yawning functions as a thermoregulatory mechanism, helping to cool the brain by increasing blood flow to the head and releasing excess heat. Conversely, some researchers believe yawning acts as a social signal, a non-verbal cue that signals fatigue or the need for alertness within a group. The contagious aspect of yawning-where seeing, hearing, or even thinking about yawning triggers others to yawn-has been well documented across species, including humans, chimpanzees, dogs, sheep, and elephants. For example, a 2013 study observed that chimpanzees in captivity would yawn repeatedly in response to videos of other chimps yawning, hinting at a deep-rooted social or neurological basis. Despite these insights, the precise reasons why yawning is contagious remain elusive, prompting ongoing scientific curiosity.

Understanding contagious yawning could illuminate broader aspects of social communication and empathy in both humans and animals. The recent experiment with robots adds a new dimension, suggesting that the phenomenon might not solely depend on biological cues but could also involve visual or behavioral mimicry mechanisms that extend to artificial agents.

As Joly-Mascheroni notes, “Contagious yawning might have evolved as a non-verbal form of social bonding or communication, helping groups synchronize behaviors or reinforce social cohesion. Studying how this response occurs with robotic stimuli could provide valuable insights into the evolution of social cognition.”

How Robots Are Changing Our Understanding of Animal Behavior

The experiment began with the creation of a life-sized, silicone-based human head equipped with a motorized mouth capable of mimicking three expressions: neutral, open-mouthed, and yawning. This “android” was powered by 33 motors that simulated facial muscle movements, allowing it to perform realistic yawns by opening its lips, closing its eyes briefly, and returning to a neutral state-all within a span of about 10 seconds. The design aimed to replicate human yawning as convincingly as possible, though its unsettling appearance might have made it seem more like a malfunctioning robot than a natural face.

Researchers then introduced this android into a room with 14 adult chimpanzees, aged between 10 and 33 years. During separate 15-minute sessions, each chimpanzee was exposed to one of the three facial expressions displayed by the robot. The results were striking: 8 of the 14 chimpanzees (57.1%) responded to the robotic yawn by yawning themselves. The likelihood of yawning increased when the android’s mouth was fully open, mimicking a genuine yawn. Interestingly, many of these primates also exhibited behaviors associated with preparing for sleep, such as lying down or gathering bedding, indicating that the robotic yawn might serve as a social cue for rest or relaxation.

While the exact reason why the chimps “caught” the robotic yawn remains speculative, scientists propose several theories. One possibility is that the chimps simply mimicked the robot, much like humans often mirror each other in social settings. Alternatively, the robotic yawn might have triggered an automatic neural response-an involuntary “realization-motion coupling”-that caused the chimps to yawn without conscious intent. This suggests that even artificial stimuli can activate innate social or biological mechanisms related to yawning, hinting at a deeper evolutionary function.

The Surprising Complexity of Yawning and Its Implications

The discovery that robots can induce contagious yawning in animals broadens our understanding of this behavior’s scope and significance. It challenges the notion that yawning is solely a biological reflex tied to fatigue or temperature regulation, opening the door to new hypotheses about its role in social bonding and communication. As research continues, scientists hope to unravel whether the response is driven by visual mimicry, automatic neural processes, or a combination of both.

Ultimately, these findings could have profound implications for fields ranging from robotics and artificial intelligence to animal psychology and evolutionary biology. They suggest that even non-living entities can influence social behaviors, highlighting the intricate ways in which communication and social cues have evolved across species-and now, perhaps, across machines as well.