Negative results are really hard to do right, and even harder to do interestingly. There are so many possible confounders in experiment design and execution th

Negative results are really hard to do right, and even harder to do interestingly. There are so many possible confounders in experiment design and execution that they generally aren't worth evaluating. So we choose to spend our time reviewing and evaluating those experiments that do seem to have at least some chance of saying something interesting. Even then, though, depending on the discipline, if the researcher did everything perfectly, they're still saying that there's a 5% or some% chance that they just "got lucky" and there is no underlying effect at all.