Contrary to popular belief, cats may not understand the emotional nuances in human voices, according to a new study. Researchers found that felines appear unable to distinguish between different human vocalizations, such as laughter, sobs, screams, or shouts. Instead, cats tend to react with a generalized state of moderate stress, regardless of the emotion conveyed.
While many domesticated animals, including dogs and horses, have developed the ability to interpret the emotional tone of human voices, cats seem to process these sounds differently. The study observed 20 domestic cats in their homes, playing them pre-recorded human vocalizations. Researchers noted reactions by observing the cats' movements, posture, eye dilation, ear position, and tail movement. Consistently, the cats exhibited signs of moderate stress, such as sideways ears, dilated pupils, and twitching tails, irrespective of whether the sound was a cry of distress or an expression of happiness.
Further investigation involved observing which way the cats turned their heads after hearing the sounds. This behavior can indicate which hemisphere of the brain is processing the stimulus. Studies on other animals show a preference for head turns based on the emotional valence of a sound; for instance, cats may turn their heads to the right when hearing purring (processed in the left hemisphere) and to the left when hearing frightening sounds like barking (processed in the right hemisphere). However, in this study, cats did not show a directional head-turning preference when exposed to human emotional vocalizations. This suggests that cats do not process these sounds in a specific, specialized part of their brain.
Lead author Dr. Serenella d'Ingeo of the University of Bari Aldo Moro suggested that human vocalizations may not be considered "sufficiently informative" for cats to warrant processing in a dedicated hemisphere, unlike the more distinct sounds from other cats. The researchers posit that cats might prioritize the intensity of emotional arousal over the specific emotion being expressed. This heightened alertness could be an evolutionary survival mechanism, preparing them to react quickly to potentially relevant social situations, a strategy that may have been adapted from their wild ancestors who were both predators and prey.
While the study indicates cats may not discern specific emotions from voices alone, it does not negate their ability to understand human emotional states. Previous research has shown that cats are sensitive to the emotional cues of their familiar caregivers, especially when vocalizations are paired with facial expressions and body language. The quality of the human-cat relationship and the presence of visual cues may play a crucial role in a cat's ability to interpret their owner's feelings.
Unlike dogs and horses, which evolved in more stable social systems and may be better equipped to extract detailed emotional information from unfamiliar individuals, cats are described as "facultatively social." Their social behavior depends on environmental factors. This difference in social evolution may contribute to their distinct method of processing human voices, adopting a more cautious approach that prioritizes general vigilance over immediate emotional differentiation.