If you’re thinking that the monkey in the above photo looks thoughtful, then you’d be right. A recent study has determined that monkeys have both a conscious and non-conscious mind quite like those of humans.

In their study, a joint Hebrew University of Jerusalem and Yale University team devised a novel scientific tool to examine levels of perception that they tested on humans and monkeys. As reported in the journal Proceedings of the National Academy of Sciences, both reacted the same.

To distinguish between the two levels of perception in monkeys, the researchers created tasks whose results would differ based on the thought process recorded.

“We started with humans and then performed the same test on monkeys,” explains Dr. Shay Ben-Haim, a joint postdoctoral fellow of the two universities.

“Each test involved a stimulus, in this case, a star, that was either presented on the right or left of the screen. The subjects would then be rewarded – points for humans and treats for animals – to look at the opposite side of the screen from where the star appeared.”

In one test, the star appeared clearly on the screen and the people and monkeys were able to consciously process that it was there. In another test, the star appeared and disappeared so quickly that it was processed without reaching subjects’ conscious awareness.

“What we were able to determine is that if the stimulus was consciously perceived, the subjects, both humans and monkeys, were able to learn to look at the opposite side of the star very quickly. But when it was processed non-consciously, subjects displayed a different pattern of responses – they continued to look at the star location, consistently failing to learn to look at the required opposite location,” Ben-Haim says.

This, the researchers say, shows that mankind is not alone in the animal kingdom in this regard, and prompts further research into other animals’ consciousness and non-conscious processes.