Ladies, boys really do have cooties.

Don’t believe us? Just take a look at a study published this week that sampled 90 offices in the US and found a significantly larger amount of bacteria on males’ desks, computers, and chairs than on females’.

For the study, researchers swabbed samples from chairs, phones, computer mice, keyboards, and desktops from offices in New York City, San Francisco, and Tucson. They found notable differences of bacteria abundance between genders, surface types, and cities.

Males had approximately 10 percent more bacteria on their office surfaces than women. Researchers noted a few possible reasons, including that “men are known to wash their hands and brush their teeth less frequently than women, and are commonly perceived to have a more slovenly nature.” Others potential factors could be men’s typically larger size than women, and simply being “less hygienic.”

But both genders should consider cleaning their phones and chairs more often, as they were the two surfaces that were the most contaminated. Keyboards, computer mice, and desktops were the surfaces least likely to be contaminated, respectively.

The city with the cleanest offices? San Francisco. New York City offices had the most bacteria, although somewhat surprisingly, Tucson wasn’t far behind. Researchers also found a variety of bacteria types in Tucson compared with the other two cities. While most bacteria found in all offices were from humans, researchers said Tucson’s variability was probably due to its climate and desert soils.

Unfortunately, DC wasn’t involved in the study, so who knows where we’d fall on the scale? Truth is, we’re not even sure we want to know.

The full study is available at PLoS ONE’s website.