One theory developed by psychologists working within the biological approach is the idea that males have better spatial ability than females. Spatial ability is the ability to mentally manipulate 2-dimensional and 3-dimensional figures. One way in which spatial ability can be operationalised is in the form of mental rotation test. A mental rotation test requires participants to identify rotated versions of a target stimulus. Mental rotation usually takes place in the right cerebral hemisphere, in the areas where perception also occurs. Mental rotation can be separated into the following cognitive stages (Johnson 1990): 1) Create a mental image of an object 2) Rotate the object mentally until a comparison can be made 3) Make the comparison 4) Decide if the objects are the same or not 5) Report the decision. See below for an example.
Shepard and Metzler (1971) have identified sex differences in performance on mental rotation tasks. Males perform better than females (faster and making less mistakes).
For this piece of research a quasi experiment is conducted because the variable that makes one group different from the other is gender i.e. one condition will be male and the other condition will be female. Since gender is something that cannot be altered, the groups are pre-determined by their biological sex, therefore making it a naturally occurring variable. Any experiment that involves the investigation of a variable like the effect of gender on behaviour is called a quasi experiment because the conditions to which participants are assigned is based on a natural phenomenon. In a quasi experiment the independent variable is decided by something beyond the experimenter’s control.
The aim of this study is to conduct a partial replication of Shepard and Metzler (1971)) research in order to investigate whether sex differences exist between males and females for spatial ability. The research question is: ‘Do males have better spatial ability than