overlooks the possibility that people who consistently use sunscreen lotions spend more time in the sun, on average,
Why this is right
Since this starts with fails to consider / ignores the possibility, we can ask ourselves whether this idea qualifies as a weakening Objection. It does, because if the people who use sunscreen spend more time in the sun than people who don't, it's not fair to compare these two groups. The former group is at a much higher risk for skin cancer (since they get more exposure to the sun). If none of them wore any sunscreen, then the people exposed to more sun would have higher rates of skin cancer. The fact that wearing sunscreen brings their cancer rates down to the level of people who have less exposure to the sun shows that the sunscreen is working. On Anti-Causal arguments, we're typically lodging one of two (often related) objections: 1. It would be even worse/better without X 2. These two groups/situations aren't fair to compare Here, we're sort of doing both. These two groups aren't fair to compare because the sunscreen group has a much higher underlying risk of skin cancer due to their greater risk of exposure. Thus, their rate of skin cancer would be even higher if they weren't wearing sunscreen. We can also think of this as offering an Alternate Explanation for the Curious Fact. The Curious Fact was, "How come sunscreen users have the same cancer rate as non-sunscreen users?", and the author's Explanation was, "Because sunscreen doesn't actually help block cancer causing radiation", and here our Alternate Explanation is, "no, the reason they have the same rate is because sunscreen users start out at a much higher risk of skin cancer".
Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.