AQA Psychology for A Level Year 2 - Student Bk

Methods: The maths bit 2 1. Write a suitable hypothesis for this investigation. ( 2 marks ) 2. Which statistical test should you use to analyse the data in Table 2? Justify your choice. ( 3 marks ) (See pages 70–71) 3. Work out the calculated value using the statistical test you identified in 2. Explain whether the result is significant and how you arrived at this decision. ( 4 marks ) 4. State the overall conclusion that can be drawn from the investigation. ( 2 marks ) 5. Explain one way in which the reliability of the finding from this investigation could be assessed. ( 3 marks ) @ookx hs @ookx hs Table 2 shows example data collected for participants’ 2D:4D ratio and the time taken to run 100 metres. Participant 1 2 3 4 5 6 7 8 9 10 2D:4D ratio 0.82 0.85 0.91 0.88 0.98 1.01 0.99 1.12 1.16 1.23 Time taken to run 100 metres (sec) 11.6 12.1 13.6 12.9 13.6 13.9 14.4 14.0 15.6 18.2 I’ve heard of someone winning a race ‘by a nose’, but by a couple of fingers . . . Hmm. The practical bit ‘Digit ratio’ is the ratio of the lengths of different fingers measured from the midpoint of the bottom crease (where the finger joins the hand) to the tip of the finger. It has been suggested by a number of researchers that the ratio of the 2nd ‘index finger’ (the one you use for pointing) and the 4th ‘ring finger’ is affected by exposure to androgens, e.g. testosterone, whilst in the womb, with lower 2D:4D ratios pointing (no pun intended) to higher prenatal androgen exposure. Researchers investigating 2D:4D have linked digit ratio to a wide range of behaviours including ADHD, schizophrenia, depression, alcohol dependency and video game addiction. Why running speed? Clearly, none of the behaviours listed above are suitable territory for a study investigation. However, a study by Manning et al . (2001) found that superior sporting ability in male participants was correlated with l ow index finger to ring finger ratio (a negative correlation ). This is based on the theory that high testosterone (low 2D:4D ratio) may lead to the development of attributes that are useful in the sporting arena – including competitiveness and a general ‘will to win’. Manning et al .’s study focused on football ability in males, in particular professional footballers who had represented their country. It’s probably a safe bet to assume that you don’t know that many professional footballers (and even fewer that have reached international standard), so your task is to examine the relationship between 2D:4D ratio and how fast your male and female friends can run 100 metres. Measuring the 2D:4D ratio The 2D:4D ratio is calculated by dividing the length 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. It is likely that the lower 2D:4D ratios will be those of the male participants in your study – but not necessarily. There are wide individual differences in digit ratio and these may vary within and between the genders. Once you have measured and recorded 2D:4D ratios for all of your participants, you are ready to start the race. Run participants, run ... One thing we should have mentioned is how many participants you’ll need. One of the co- variables will be determined by performance in a sprint – with everyone running at the same time – a cast of thousands is not really appropriate. It would be OK to organise a series of races if you manage to recruit quite a lot of participants but individual time trials are not an option. The point is that participants must be given the opportunity to show how competitive they are by running against each other, rather than on their own ‘against the clock’. You’ll need a bit of a help Despite your best efforts, it will be difficult to replicate Olympic-style running conditions in your 100m race, and without access to sophisticated recording equipment, you’re going to have to rely on a little help from your (non-participant) friends. Make sure you have enough people present on race day to ensure everybody’s time is reasonably accurately recorded. Practical idea 2: Digit ratio and running speed The aim of this study is to see if there is a correlation between a person’s index finger (2nd digit – 2D) and their ring finger (4th digit – 4D) ratio and how fast they can run. In other words, is 2D:4D ratio related to sporting performance – specifically the time it takes someone to run 100 metres? This is based on a study by Manning et al . (2001) who found that high 2D:4D ratio in males was associated with reduced performance in sport. The maths bit Overall, at least 10% of the marks in assessments for Psychology will require the use of mathematical skills and at least 25% in total will involve research methods. Don’t avoid it! practical corner 53 •