Biological Practical Flashcards
Outline the rational and the aim of your study
The rational is 2D:4D digit ratio has been linked to pre-natal exposure to testosterone. Our aim was to see whether there was a correlation between 2D:4D digit ratio (measured in cm) and self reported aggression levels on a scale of 1-10
Describe your sample and the sampling method you used for your study
Our sample consisted of 13 (1 male and 12 females) Caucasian participants aged 16-17 all of whom lived in the same area (Bristol) in the uk and were privately educated at the same school. The sampling method was opportunistic, as we asked the pupils in our psychology class to take part.
What was your research/experimental/alternative hypothesis
There will be a significant correlation between 2D:4D digit ratio (measured in cm) and self reported aggression on a scale out of ten, whereby 0=no aggression, 10=high aggression
What was your null hypothesis for the study
There will be NO significant correlation between 2D:4D digit ratio (measured in cm) and self reported aggression on a scale out ten, whereby 0=no aggression and 10=high aggression. ANY RELATIONSHIP WILL BE DUE TO CHANCE
What were your operationalised variables
a) Levels of aggression as measured by a self reported score out of 10, based on the past month, whereby 0=no aggression and 10=high aggression
b) 2D:4D digit ratio is calculated by dividing the length (in cm) of the index finger of the right hand by the length of the ring finger of the right hand. (A longer index finger will result in a ratio higher than 1, while a longer ring finger will result in a ratio of less than 1)
Outline two methodological strengths if your experiment
We considered the ethical implications and gained informed consent. For example, we informed all of our participants of the full aims of the study, which was investigating the relationship between 2D:4D finger ratio and self reported levels of physical aggression over the past month. Therefore ensuring all participants were aware of what they were consenting to take part in, so there was no deception.
We used a reliable method to gain 2D:4D finger ratio measurements as the instructions were standardised. For example all participants were asked to measure the length of their index finger in cm from the crease to tip and ring finger from crease to tip (excluding fingernail length), before dividing the index finger length by the ring finger length. Therefore, this can be repeated and is reliable
What inferential test did you use to analyse your data
We used spearman’s rho because:
The test was of correlation, to see if one covariable (2D:4D digit ratio) was related to the other (self reported levels of aggression on a scale of 10)
Our data was ordinal level and above as we used ratios, based on measurements of each participants index and ring finger on their right hand in cm and numerical measurements of rank 1-10, whereby 1=low aggression and 10=high aggression
The design was repeated measures as we correlated pairs of data, with measurements of the two covariables taken from each participant
Outline one weakness of your practical
One weakness was our method to take measurements of finger length as each participant took a measurement, using a rigid 2D ruler of their finger lengths. This could have been innaccurate due to the awkwardn fit of the ruler on the 3D finger. Also, they took a single measurement, which could have been erroneous but wasn’t checked. As pps were aware of the aim of the study, and were measuring their own finger length , these could have been subjective and again, weren’t checked. For these reasons the reliability and validity of the study can be criticised as the data may not have been accurate.
