Clicking 'Expand' should collapse all traits/interests in given section if all of them are already expanded.
Right now, one can only use Expand button for expanding traits/interests, but collapsing them has to be done manually - although there is an argument that you can just collapse the whole section of profile, I think ability to read context for them and then collapse to have a quick overwiev for further reference would be useful. At worst, it is a convenience feature that is logical to have (and, to be honest, I fully expected it to work like that).