Most of us remember the classic LEGO dude. Small, yellow, smiling. He had a few basic poses and a single, smiling face. But as LEGOs have gotten more and more varied, the company has given the little yellow dude more expressions. One recent study looked at those expressions, and found that more often than not the new LEGO faces are angry.

Here’s the basic setup of the study, from Research Digest:

Bartneck obtained images of all 3655 Minifigure types manufactured by LEGO between 1975 and 2010. The 628 different heads on these figures were then shown to 264 adult participants recruited via Amazon’s Mechanical Turk online survey website. The participants’ task was to categorise the emotions on the heads in terms of the six main human emotions, and to rate their intensity.

What they found was that there’s been a huge increase in the variety of faces, and while the majority of them are happy (324), the next most common expression is angry (192). Then, in order, you get sadness, disgust, surprise and fear. But the trend is towards angrier faces and away from happy ones.

This probably has to do with the increase in themed collections that go along with action movies and video games, many of whom are fighters. The researchers also found an increase in the amount of weaponry LEGO characters come with. Bartneck and his team express concern about how this shift to angry faces might impact children, writing “We cannot help but wonder how the move from only positive faces to an increasing number of negative faces impacts how children play.” Their research, though, didn’t attempt to investigate any links between angry LEGOs and angry kids.

More from Smithsonian.com:

Celebrating 80 Years of LEGO

The World’s Great Structures Built With Legos