The abstract of the paper sounds like this isn't actually a counterclaim, it is only a questioning of the claim being made. The author isn't saying that the Spartans didn't systematically "kill weak babies." She is saying there doesn't appear to be much evidence that they did, and given evidence that it wasn't common in general in ancient Greece, the claim is suspect.

Sparta wasn't common like any of the contempory cities. Sparta has unique militaristic society. Hence the writer should have furnish proof within Sparta and not use proxies to generalize the same. Canada and Mexico are next to USA. The things happening in USA are hard to be extrapolated from Canada or from Mexico. You can't be reasonable to say American loves maple syrup and have cartel rampant running the drug trades simply because it is common in Canada or Mexico.

> A claim or a counterclaim (is there even a distinction?) warrants the same amount of proof.

Yes that is exactly what I was saying.

Then I don't understand you.

You wrote:

> Is there a name for being arbitrarily biased against a counterclaim?

Who is arbitrarily biassed against a counterclaim in your opinion here? Debby Sneed who wrote the study? Andrew Curry who wrote the science.org article about the study? gadflyinyoureye who wrote the comment your comment is responding to? Someone else?

> The simple fact that this is posed as a counterclaim itself seems to invoke skepticism...

As it should. I don't see the bias here. Are you saying that someone accepts claims without skepticism but not counterclaims? Who?

I may not have expressed myself properly. Instead of saying arbitrarily biased against the counterclaim, I should have said arbitrarily biased for the implied claim that is being countered.