5/6. Number 3 had me confused. Hoping to try out a few more like it to built more mental framing.

Does anyone have any tips for navigating questions like #4? I got it incorrect because I interpreted it as "Because no statistical evidence is provided", humans act selfishly and unselfishly to an equal amount or are unselfish more often. Obviously this is wrong, and the grammatical explanation makes sense, but it's often I find myself tripping up on questions like this that don't follow the conventions of Canada/English grammar or have Oxford commas.