When you look at the photo above, do you see a face? If you do, you experience a condition known as pareidolia: a tendency to attribute meaning to a stimulus. Seeing faces on inanimate objects is a common occurrence, and most people seem to perceive these faces as male rather than female.

The findings of a recent paper that observed that facial pareidolia, or “misleading faces,” trigger perceptions beyond just detecting a face, point in this direction. People attribute to these perceptions features such as age, emotional expression, and gender. The authors of the study, published in the Proceedings of the National Academy of Sciences, concluded that non-human faces need extra “feminine” details to be perceived as female. In other words, in most cases, the perceived face is the male face.

The results come from large-scale behavioral experiments of more than 3,800 adults from the United States that tried to determine the perceived gender of misleading faces. Their responses showed that people were significantly more likely to accept an inanimate object with a misleading face as a man rather than a woman. They also correlated expressions and age with facial pareidolis: They were much more likely to perceive objects as young, happy, and male rather than old, disgusted, or female.

In different experimental designs, they tested whether the color path of the image or the photographed object explained gender bias, but found that the corresponding object images of illusory faces did not elicit the same perception. That is, a simple photograph of a fried egg did not reveal the same biased perception as a fried egg with a misleading face.

“Collectively [the results] showed that deceptive faces have a different emotional expression, age, and gender,” the study authors wrote. “This bias, if robust and reliable among observers, provides important implications for understanding how gender perception is processed in the human brain, especially given that these stimuli have no biological sex.”

Instead, this significant gender bias appears to be indicative of an innate or learned image-processing method that sees us assigning a male gender to anything that vaguely resembles a face.

Of course, this research also has some limitations. First of all, the participants of the study only come from the USA. This assumed perception or bias may differ in other countries or cultures.

It remains unclear why this bias exists, but lead author Susan Wardle, speaking to Science News, highlights the emoji and Lego examples as evidence of a similar bias in our daily lives. In both examples, characters are assumed to be male by default, unless some lashes, larger lips, makeup, or other “feminizing” features are included in the equation…