Q15 - Studies of brain lateralization in animals

[ivank]

Please explain why it is not A?

[sumukh09]

In this question we're trying to weaken the argument that the finding that animals are equally likely to be left handed as they are right handed is suspect. We want to weaken the idea somehow that the finding is not suspect and dogs are just as likely to be left handed as they are right handed.

A doesn't do this since it tells us that dogs are just as likely to scratch themselves with the left leg as well as the right leg. BUT what about the fact that dogs always shake their hands using their right hand? This still would make the finding in the argument suspect because dogs are showing a preference for a right side favouring limb ie) the right hand. If it's equally likely that dogs will scratch themselves with the right leg as it is the left leg then this does nothing to the counterexample of the dogs shaking predominantly with their right hands.

E on the other hand gives us a defense of the counterexample because we're told in the stimulus that most human beings are right handed so that explains why dogs almost always shake with their right hands -- it's because they are influenced by their right handed trainers and not because they have a natural preference for their right hand.

[maryadkins]

In this question we're trying to weaken the argument that the finding that animals are equally likely to be left handed as they are right handed is suspect.

Correct! The core is:

dogs show a preference for shaking with the right paw --> finding that mammal handedness is 50/50 is suspect

As for why (A) fails to do this, sumukh09, you're also correct that:

A doesn't do this since it tells us that dogs are just as likely to scratch themselves with the left leg as well as the right leg. BUT what about the fact that dogs always shake their hands using their right hand? This still would make the finding in the argument suspect because dogs are showing a preference for a right side favouring limb ie) the right hand. If it's equally likely that dogs will scratch themselves with the right leg as it is the left leg then this does nothing to the counterexample of the dogs shaking predominantly with their right hands.

(B) isn't a strong weakener because even if we're only speaking about front paws, the dogs are still showing a preference for the right one. That's what we want to challenge, and (B) doesn't.

(C) Good for them! But just saying they're not like people doesn't do anything to the argument. They could still have a preference for using the right paw for some other reason.

(D) Once again, great. But why do they shake more with the right paw?

(E) once again, great job sumukh09:

E on the other hand gives us a defense of the counterexample because we're told in the stimulus that most human beings are right handed so that explains why dogs almost always shake with their right hands -- it's because they are influenced by their right handed trainers and not because they have a natural preference for their right hand.

[WaltGrace1983]

Hypothetical question but would (A) be a weakener of the conclusion? It seems like it would be so because it tells us that dogs don't exclusively favor one limb or the other.

[ohthatpatrick]

(A), if anything, would strengthen the argument's conclusion.

The study suggests that about 1/2 of dogs will be left handed and 1/2 will be right handed.

The conclusion says that this study's finding is probably wrong.

(A) seems to suggest that dogs are neither left handed nor right handed.

Does (A) agree with the study? No. (A) seems to describe dogs that show no preference for one leg or the other. Thus, (A) goes AGAINST what the study is suggesting.

If (A) goes AGAINST what the study is suggesting, then it would actually strengthen the conclusion (the conclusion says the study is probably wrong).

Naturally, none of this matters to the question.

And, (A) doesn't really give us any reason to believe that the dogs observed are "neither-handed". After all, being left-handed means you show a PREFERENCE for the left limb, not that you use the left limb exclusively. (A) doesn't give us any information about whether the frequency of left leg scratching is more or less than that of right leg scratching. So the fact that sometimes dogs scratch with left, sometimes with right, has no power to affect this whole left-handed vs. right-handed conversation in any way.

Hope this helps.

[coco.wu1993]

I don't see E is a strong answer. The stimulus stated "it has long been noted", "almost always". It's reasonable to assume that a large proportion of dogs don't learn to perform tricks at all, so E cannot explan why shaking right hands is a normal state of dogs. C certainly isn't a perfect answer, but it is the strongest one among the five. Thoughts?

[maryadkins]

The argument is assuming that the fact that dogs shake with their right paws means some kind of innate thing about dogs. (E) suggests this isn't true. That's how it is a defense and why it is correct.

(C) leaves way too much unknown. If dogs don't feel stigma, so what? They could still have a natural, innate preference for using their right paws.

[coco.wu1993]

The argument is assuming that the fact that dogs shake with their right paws means some kind of innate thing about dogs. (E) suggests this isn't true. That's how it is a defense and why it is correct.

(C) leaves way too much unknown. If dogs don't feel stigma, so what? They could still have a natural, innate preference for using their right paws.

I think I got the point! C does not attack the counterexample at all. Thanks!