2D4D Practical: Bio 2 Flashcards
Define the term co-variable
The two variables in a correlational study which have been measured
What does a correlation coefficient tell us about a set of data?
the strength and direction of a correlation
A psychologist wants to investigate whether internet usage decreases with increased age.
Write an operationalised non directional hypothesis for this study
There will be a significant correlation between estimated hours spent on the Internet per week and age of Internet users in years and months
What is the strength of a correlation between 0.0 - 0.3
Weak
What is the strength of a correlation between 0.3 - 0.7
Moderate
What is the strength of a correlation above 0.7
Strong
If we wish to carry out an inferential statistical test on IQ scores from test and avg earnings per annum which test should be used and why? (3 marks)
Spearman’s correlation coefficient because we are carrying out a test on the correlation between 2 variables of average earning and IQ scores.
Also we have at least ordinal level data as earnings are measured in £K and IQ using a standardised test.
Give a example of previous research which indicates that there is a relationship between testosterone and aggression
Mazur (1983) indicated that throughout their teenage years males testosterone increases and there is a strong positive correlation with aggressive behaviour and inter- male fighting.
What is the aim of your practical investigation in biological psychology?
To investigate using a correlational study weather testosterone levels can be linked to aggression levels
Operationalise co-variable 1: Testosterone levels
2D (index finger) 4D (ring finger) ratio averaged across both hands and measured in millimetres
Give a strength of using 2D/4D measurement
P=The method of measurement is easy to replicate using the standardised procedure for the 2D/4D ratio.
E=This is a strength because it can lead to higher reliability which increases the scientific credibility of the measure of testosterone.
Give a weakness of using 2D/4D measurement
P= The 2D/4D ratio is a measure of levels testosterone levels a person was exposed to in the womb rather than a measure of current testosterone levels.
E=this is a weakness because it lowers internal validity as we are trying to link testosterone levels to current aggression levels.
A more valid measure of testosterone for this study would therefore be one that gives an indication of current testosterone levels
Operationalise co-variable 2: Aggression levels
aggression rating using the Buss Perry Aggression Questionnaire (1992)
Give a strength of using the Buss Perry Aggression Questionnaire as a measurement for aggression levels
P= It produces quantitative data from a questionnaire with a 5 point likert scale giving each P an aggression score
E=this is a strength because it provides a fairly objective numerical measurement of aggression and allows for statistical analysis of findings
Give a weakness of using the Buss Perry Aggression Questionnaire as a measurement for aggression levels
P= The participants all had fully informed consent and are psychology students and this may bias their answers on the aggression questionnaire
E =this is a weakness because demand characteristics are very high so the answer given may be what the Ps think the researcher wants . This lowers internal validity because we end up with a score that is not an accurate measure of a Ps aggression
Identify the sampling technique used in your correlational study
Opportunity sampling
Describe the sample used in your study
The sample was made up of 20 psychology students from my lower 6th class at a 6th form college in Surrey.
There were 14 females and 6 males.
All of the sample were between 16
and 17 years of age.
Give one strength of the sampling methods in this study
P= One strength of the sample was that it was an opportunity sample. E= This is a positive because, as we were working to a tight deadline with only 4 lessons to complete our correlational practical C=Therefore, it allowed us to collect our data on testosterone levels and aggression levels in an efficient manner.
Give one weakness of the sample in this study
P= One weakness of the sample
was that it was made up of more
females than males
E= This is a problem because, as we are interested in testosterone levels, and how they link to aggression, more males in the sample may have given us a different result
C=Therefore, this may mean any correlation we find between testosterone levels and aggression
levels may not be generalisable to the target a population as our sample is made up of mainly females
Explain why some ethical issues were not addressed is this study
1. General respect- low risk This is because it was a class practical and the students and teacher treat each other with respect = no specific action needed
- Observational research
Was not addressed as there was no observations in this study so was not applicable.
State which ethical issues were were identified as risks in this study and how they were addressed
- Confidentiality & 7. Protection of participants- Moderate risk: Ps may not want their aggression levels or testosterone levels seen by all members of the class (embarrassed; shy)
This was addressed by ensuring that all data was collated anonymously by the teacher: each P given only a number.
Describe the materials used in your study
1) Standardised instructions were give to each participant to enable them to measure the 2D and 4D ratio on each hand as a measure of testosterone.
2) A online version of Buss Perry Aggression Questionnaire was used Ps had to answer questions on a Likert scale out of 5 collecting quantitative data in silence.
What is the alternate hypothesis of your study?
There will be a significant negative correlation between testosterone levels measured by the 2D4D ratio and aggression levels measured by the Buss Perry questionnaire
What is the null hypothesis for your study?
There will be no significant correlation between testosterone levels measured by the 2D4D ratio and aggression levels measured by the buss perry questionnaire
What is the test appropriate for your correlational research practical?
Spearman’s Correlation Coefficient
Give 3 reasons why a Spearman’s Correlation Coefficient is the appropriate test for your correlational study
1) We are testing for a correlation between two-variables: Testosterone levels and aggression levels.
2) The data is at least ordinal level. We measured testosterone levels using the 2D4D ratio in mm. Aggression levels were measured using the Buss Perry Q using a 5 point Likert scale.
3) The data was related as it was in pairs. Data came from the same participant.
What does your calculated R/s value tell you about the strength and the direction of the correlation between your two co-variables?
0.7
A very strong positive correlation between testosterone levels (measured by the 2D4D ratio in mm) and aggression levels (measured by the Buss Perry Questionnaire)
What were the conclusions in relation to your results?
The results showed that there is a significant relationship between testosterone and aggression. This is because the Rs value was 0.7 which was higher than the critical value which was 0.442. This was for a 0.05 significance level for a one tailed test when N was 10.
Our results did support the original findings on previous research.
Give one strength of this study
The practical was high in reliability this is because standardised procedures were used. For example the instructions given to participants to measure their 2D4D ratio were the same.
Give one weakness of this study
The practical has low generalisability. For example the sample were all psychology students from the ages of 16-17.
Give one way this study could be improved.
Use a wider range of people to have a more generalisable sample. This could be done by asking participants from different age groups and those taking different subjects/ occupations
