Unperturbed , the participants , having been shown only the environmental video , rated the child ' s ability level as hovering close to her known school grade . They rated ‘ working-class ’ Hannah as slightly below fourth-class level , and ‘ middleclass ’ Hannah as slightly above . Remember , they had all been offered a ‘ don ’ t know ’ option if they felt they had insufficient information .
Background only
5 4 3 2 1 0
4.3 4.29 3.98 3.9 3.85 4.03
Liberal arts Reading Maths Lower socio-economic group
Higher socio-economic group
The perceived differences between the two Hannahs were 0.32 of a grade level for liberal arts , 0.39 for reading , and 0.18 for maths . These are not insignificant differences — for a child in fourth class , being 39 %, or 32 %, or even 18 % of a grade behind her classmates would be a noticeable distinction .
The two groups were then shown another video recording . In this case , both saw the same recording , in which Hannah responded to 25 achievement-test problems ranging from second- to sixth-class level . Participants were told that the test included ‘ easy , moderate , and difficult problems ’. Hannah ' s performance was prearranged to present an inconsistent picture of her abilities . She answered both easy and difficult questions correctly as well as incorrectly . She appeared to be fairly verbal , motivated , and attentive on some portions of the video recording and unresponsive and distracted on other portions . The tester provided little feedback about Hannah ' s performance .
Participants , having seen the ‘ objective ’ evidence of Hannah being tested , became much more confident in their judgement . Rather than judging the two ‘ Hannahs ’ equally , however , as logic would suggest , they showed a reliably greater distinction between ‘ working-class ’ and ‘ middle-class ’ Hannah on all three indices : 1.04 for liberal arts , 1.06 for maths , and 0.96 for reading . Remember , all participants had seen the same recording of the same girl giving the same answers to the same questions on the same test .
Nevertheless , those participants who had seen the video of Hannah suggesting that she was from a lower socio-economic background judged her to be about a full year behind the grade given to Hannah when the graders thought she was from an affluent background .