A new study has found that Lego characters released since the early 1990s are proportionately angrier.
Authors of the study hypothesized that the spike in negativity could be related to the release of more thematic Lego sets - such as pirates or 'Harry Potter' - that include weapons, along with miniature figurines representing "good guys" and "bad guys," the Japan Times reported.
"It is our impression that the themes have been increasingly based on conflicts," researchers Christoph Bartneck, Mohammad Obaid and Karolina Zawieska wrote.
After cataloguing and photographing the 3,655 Lego characters released between 1975 and 2010, the researchers asked 264 American adults to characterize the figures' expressions as angry, happy, sad, disgusted, surprised or fearful.
Bartneck, who will present the paper on his findings at the First International Conference on Human-Agent Interaction in Sapporo, found a proportional growth of angry faces since the early 1990s.