Voice assistants from Apple, Google and Microsoft might help a person keep up their life organized, but a new research paper shows the technologies have an IQ that’s less than a six-year-old’s.

Researchers Feng Liu, Yong Shi and Ying Liu analyzed voice assistants Google, Baidu, Sogou, Apple’s Siri, Microsoft’s Xiaobing and others throughout 2016. Out of all the different voice assistants, Google’s and Baidu’s artificial intelligence technology were smarter, researchers said. However, they’re not as smart as a six-year-old, who has an IQ of 55.5.

“[...] The artificial intelligence systems produced by Google, Baidu, and others have significantly improved over the past two years but still have certain gaps as compared with even a six-year-old child,” the researchers wrote in the paper.

Google’s artificial intelligence technology had an IQ of 47.28, Chinese AI technology Baidu followed with 32.92. Apple’s Siri turned out to have the lowest score. Bing, Microsoft Xiaobing and Siri lagged behind Google with an IQ of 31.98, 24.48 and 23.94, respectively. All the voice assistants analyzed were dumber than 18-year-olds, who have an IQ of 97.

The researchers also looked at the virtual assistants in 2014. While the voice technologies aren’t so smart, they have improved over time, experts found. Back in 2014, Google’s AI technology had an IQ of 26.25, while China’s Baidu followed at 23.5. Google was the only American company that was listed in the top 13 artificial intelligence IQs for that year.

“Perhaps more significantly, the yearly trajectory of test results will allow for a comparison of selected artificial intelligence systems with the highest-IQ humans,” the researchers wrote. “As a result, future development of the relationship of artificial intelligence to human intelligence can be judged and growth curves for each intelligence that are mostly in line with the objectively recorded measures can be determined.”

The AI to human intelligence can be measured like so:

Developmental curves of artificial and human intelligence How to measure Siri, Google, Microsoft: Developmental curves of artificial and human intelligence. Photo: Research Paper: Intelligence Quotient and Intelligence Grade of Artificial Intelligence

Apple, Microsoft and Google have been heavily investing in artificial intelligence. In 2014, Google acquired DeepMind, and most recently India’s Halli labs. Meanwhile, Apple acquired Australian company Turi in 2016, as well as Lattice in May.

The research also didn’t include iOS 11’s new Siri capabilities, since experts analyzed the assistant before the update launched. Siri now translates phrases in Chinese, German, Spanish, French and Italian, with more languages coming soon. Apple said earlier this year the improved Siri will get to know users better by understanding context, interests and how they use their device. Using the data gathered, Siri will suggest topics on the News app, improve its suggestions on iMessage and will create calendar alerts based on things booked in Safari.

Google’s Pixel 2, which will be revealed Wednesday, is expected to be smarter. Google hinted in a promo last month the device won’t be as dumb as other artificial intelligence technologies.