Question

Be Nice to Pigeons, As They Remember Your Face In a study1 conducted in Paris, France, equal amounts of pigeon feed were spread on the ground in two adjacent locations. A person was present in both sites, with one acting hostile and running at the birds to scare them away and the other acting neutral and just observing. The two people were randomly exchanged between the two sites throughout and the birds quickly learned to avoid the hostile person’s site and to eat at the site of the neutral person. At the end of the training session, both people behaved neutrally but the birds continued to remember which one was hostile. In the most interesting part of the experiment, when the two people exchanged coats (orange worn by the hostile one and yellow by the neutral one throughout training), the pigeons were not fooled and continued to recognize and avoid the hostile person. The quantity measured is difference in number of pigeons at the neutral site minus the hostile site. With measurements, the mean difference in number of pigeons is 3.9 with a standard deviation of 6.8. Test to see if this provides evidence that the mean difference is greater than zero, meaning the pigeons can recognize faces (and hold a grudge!) 1Belguermi, A., ‘‘Pigeons discriminate between human feeders,” Animal Cognition, 2011; 14: 909-914.

State the null and alternative hypotheses. Your answer should be an expression composed of symbols: =,≠,<,>,μ,μ1,μ2,p,p1,p2,0,ρ,p^,p^1,p^2,r.

H0: vs Ha:

Give the test statistic and the p-value.

Round your answer for the test statistic to two decimal places and the answer for the p-value to three decimal places.

test statistic =

p-value =

What is the conclusion of this test of hypotheses?

Do not reject H0; we find evidence that pigeons can recognize faces.

Do not reject H0; we do not find evidence that pigeons can recognize faces.

Reject H0; we do not find evidence that pigeons can recognize faces.

Reject H0; we find evidence that pigeons can recognize faces.

Answer 1

Here we have paired data so paired test will be used.

Conclusion:

Reject H0; we find evidence that pigeons can recognize faces.