Due to the relationships of the lions in the study, the researchers were able to conclude that the lions weren't trying to display dominance, but rather affection that would lead to a bond that could benefit them later on.
"These results indicate that its primary function is to maintain and strengthen social bonds between individuals," the study said.
We use hugs and affection to strengthen bonds too, but for purely friendly or romantic reasons. For lions, it also has to do with survival and staying in good standing with the group. When lions cuddle, it's not so much compassionate or adorable - it's actually very strategic.
Check out a video of lions showing off this behavior below: