Researchers in New Zealand said they analyzed the facial expressions on Lego figures from the past 35 years and discovered the faces have been getting angrier.
The team, from the University of Canterbury and the Industrial Research Institute for Automation and Measurements, said their analysis of Lego figures found most facial expressions could be categorized as happiness, anger, disdain, confidence, concern or fear, with happiness and anger being the most common.
The study, published in Proceedings of the First International Conference on Human-Agent Interaction, found angry expressions on Lego figures have become increasingly common since the early 1990s, while happy expressions have become less common.
"The work presented in this paper can lead other researchers in the field of understanding the science of play to investigate further the influence the Lego Minifigures ' facial appearance have on Lego users over time," the study's authors wrote. "We believe that the extensive and elaborate designs of faces on Lego Minifigures can also inform the designers of other agents, such as computer game characters and robots.