Biological Research Methods Flashcards
What is the rational and aim of the study?
The rational is 2D:4D ratio has been linked to pre natal exposure to testosterone.
To see whether there was a correlation between 2D:4D digit ratio (cm) and self-reported aggression levels on a scale of 1-10.
Describe the sample of the study
Our sample consisted of 13 (male = 1, female = 12) 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
Describe the sampling method of the study
The sampling method was opportunistic, as we asked the pupils in our Psychology class to take part.
What was the research/ alternative/ experimental hypotheses for the study you conducted in Biological Psychology?
H1 : there will be a significant relationship (correlation) between 2D:4D digit ratio (cm) and self-reported aggression on a scale out of ten, whereby 0 =no aggression, 10 = high aggression. Any relationship will be due to chance.
What were the operationalised variables?
A = levels of aggression as measured by a self-reported score out of 10, based on the past month, whereby 10 = very high levels of aggression and 0 = no aggression.
B = 2D:4D ratio as calculated by dividing length (cm) of the index finger of the right hand by the length (cm) of the ring finger of the right hand. (A longer index finger will result in a ration higher than 1, while a longer ring finger will result in a ration of less than 1.)
Outline TWO methodical strengths of 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: AD 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 20-4D 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 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? Justify your decision
We used Spearman’s Rho because
(i) the test was of correlation, to see if one co-variable (2D:4D digit ratio) was related to the other (self-reported levels of aggression on a scale of 10).
(ili) Our data was ordinal level and above as we used ratios, based on measurements of each participant’s index and ring digit on their right hand in cm and numerical measurements of rank 1-10 whereby 1 = low levels of aggression, 10=high levels of aggression).
(ill) 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, 2-D ruler of their finger lengths.
This could have been inaccurate due to the awkward fit of the ruler and the 3D finger.
Also, they only took a single measurement, which could have been erroneous but was not checked. As participants were aware of the aim of the study, and were measuring their own finger length, these could have been subjective and again, were not checked.
For these reasons, the reliability and validity of the study can be criticised as the data may not have been accurate.
Describe how you could overcome the weakness outlined above
We could have taken scanned images of the participants’ right hands to enable a more accurate measurement of finger length in cm, based on a 2D image.
We could have repeated the measurements three times and taken a mean average to work from. We could have used a blind procedure, with 4 disinterested colleagues measuring the finger lengths, to eliminate bias or subjectivity and to also give inter-rater reliability, as any measurements disagreed upon could have been discarded from the study.
