Example of a complex multiple independent variable hypothesis:
Example of a complex multiple dependent variable hypothesis:
In a classic study of facial attractiveness, Perrett et al. (1994) tested the Averageness Hypothesis in an effort to establish if averageness really is the critical determinant of the attractiveness of faces. Perrett et al. first collected a full face photographs of 60 young women (these photographs were taken under the same lighting conditions). One group of participants then were shown these images and asked to rate the attractiveness of each face using a 1 (very unattractive) to 7 (very attractive) scale. Next, Perrett et al used computer graphic methods to manufacture a composite face with the average shape of the whole sample (i.e. to construct the average of all 60 female faces) and a second composite face which was the average of the 15 faces that had been judged to be the most attractive by the first group of participants. Perrett et al. then manufactured what they called a ‘hyper-attractive’ composite face (i.e. a version of the composite of the attractive faces in which its attractive qualities were exaggerated or caricatured) by exaggerating (i.e. caricaturing) the physical differences in shape between the composite of all 60 faces and the composite of the most attractive 15 faces using computer graphic methods.
The hypotheses of interest in an ANOVA are as follows:
Intriguingly, Perrett et al. found that when a new group of participants were asked to rate the attractiveness of each of the 3 composite faces (the average of all 60 faces, the average of the 15 most attractive faces and the ‘hyper-attractive’ that had exaggerated attractive qualities) the hyper-attractive face was considered the most attractive of the 3. This is noteworthy because the hyper attractive face was mathematically the least average of all 3 composites. Because the hyper-attractive face was the least average of the 3 composites judged, but also the most attractive, this finding is very strong evidence that averageness is not necessarily the critical determinant of facial attractiveness. In other words, Perrett et al's findings are evidence against the Averageness Hypothesis of facial attractiveness (which proposes that ‘attractive faces are only average’) because the findings show that highly attractive faces deviate systematically from an average shape.