I think this finding makes sense. We don't yet know what the connection between shape and function is in the brain, but there must be one. Our brains wouldn't be the shape they are if it didn't help us be the people we are. It also makes sense that not all brains are the exact same shape and size. We know we are not all the same personality either. I don't think it is a stretch to then think that the difference in personality and thinking patterns arises from the structure of the brain; but it is still really cool to see a finding that can actually confirm that this link likely exists.
I wonder if this means that we can change the shape of the brain (Through surgery or other methods) and change our personalities. Lets say someone wants to be more extroverted, could they go in for a brain stimulation that somehow stretches their cortex and increases folding to make them more open and extroverted? It would be an interesting idea, but hard to test in real life as messing with the brain without knowing what is going on has dire consequences most of the time.